Robert I. Schattner, the inventor of sore-throat remedy Chloraseptic, died at 91 in Bethesda, Md. (Ricky Carioti/The Washington Post)

I attended a memorial service a few days ago at Georgetown University for one of Washington’s richest people that you’ve probably never heard of.

Robert I. Schattner died at age 91 last month in Bethesda. He was the inventor of Chloraseptic, the sore-throat remedy.

When Bob’s will is probated in the coming months, an eye-popping, nine-figure deposit will land at the Robert I. Schattner Foundation, creating a thunderclap in Washington’s philanthropic community. The bequest should make the charity one of the city’s richest.

I knew Bob for almost a decade. I wrote one of my first Value Added columns about him in 2008 after he had called to say he was ending a long career that encompassed 70 patents and trademarks and a 20-year stint on the board of First National Bank of Maryland.

He was a practicing dentist back in 1952 when a guest at a cocktail party asked him whether it was possible to disinfect the mouth after having a bunch of teeth pulled. Bob mulled it over on the ride home from the party. Then he started experimenting. Working late nights after work, he mixed combinations of chemicals in his “laboratory,” a five-gallon jug he kept behind a shower curtain in his bathtub. Eventually, he invented a mouthwash that kills germs and serves as an anesthetic for the throat. Chloraseptic was born — and a fortune began.

Bob was a gentle man who had a fondness for corny one-liners. We developed a friendship that included phone calls, a seat at his table for fundraisers and trips to several Nationals baseball games. Sometimes we sat in my seats behind the Nats’ dugout. Sometimes in Bob’s — behind home plate. Once we sat in the spacious suite of Nationals’ owner Theodore Lerner, who was a longtime friend of Bob’s.

His idle chatter involved either investing, bacteria and how to kill it, or baseball. Bob knew a lot, and he shared some of it with me — like the time he said one measure of a pitcher’s game performance was his strike-to-ball ratio. It should be 2-to-1. He was a germaphobe and turned me into one, as well. To this day, I refrain from grabbing the handrail on Metro escalators if I can avoid it.

Bob was frugal. During one Nationals game, I was getting up to go to the food stand when he reached into his pocket and pulled out two granola bars. Cheaper than ballpark food, he said.

His favorite restaurant was Old Country Buffet, hardly the eating house for the centimillionaire set. Bob’s close friend, Phyllis Bresler, told a story at the service about how Bob joined Phyllis and her parents at a prominent steakhouse: “I recall my father looking across the table laughing and saying, ‘Bob, who is foolish enough to spend $8 on a baked potato?’ Bob shook his head and said ‘I know, go figure!’ ”

Despite his great wealth, Bob, whose parents had emigrated from Austria, lived in a modest Montgomery County home that he bought for $60,000 five decades ago. He drove an aging Lincoln Town Car well into his 80s. I remember one occasion when he insisted on driving me home from a Nats game. I was terror-stricken as the 85-year-old sped through Chevy Chase at night.

One of Bob’s best friends was the late Charlie Bresler, Phyllis’s father-in-law. Charlie and Bob went back 60 years. They met at a local bankers convention. Charlie was another businessman whose low-key nature belied his success. He looked out for Bob.

I came to know Charlie and his wife, Fleur, through Bob. Charlie was a former Maryland Republican politico. He ran Bresler & Reiner, a real estate firm. Charlie was a great raconteur, dropping his latest jokes on me during frequent phone calls.

I remember one gathering at Charlie and Fleur’s apartment, which is the size of Rhode Island and filled with Fleur’s sprawling collection of American crafts. My wife, Polly, and I had finished our homemade chicken dinner and were enjoying the evening when Bob abruptly rose and said he had to go home.

What’s the rush, I asked. Bob was a creature of habit, and he wanted to go home that night to work on his investments. He was very devoted to what he called his stock charting. He explained his strategy to me, but it never sank in.

Bob’s millions began accumulating in 1962, when the onetime dentist who had a bachelor’s degree in chemistry sold Chloraseptic for $4 million. That was a bunch of money back then, but his real genius was signing on for 10 percent of the revenue for 15 years.

The money piled up. And he kept investing. Bob explained to me his love for buying into community banks and then holding on while the banks kept getting swallowed by bigger banks. He and Charlie invested together on everything from Mississippi barges to North Sea oil rigs.

Bob also had a big stake in Manny Friedman’s EJF Capital. Manny, a onetime schoolteacher and attorney, is one of the most respected investment minds around Washington. He still has the certificate from the first stock trade he made in 1961, when he was a teenager. It was a $36 profit on shares of Lorillard Tobacco.

Charlie and Bob may have been discreet, but they also shared a weakness for professional sports teams. That’s the kind of wealth they had. They both got their wishes, sort of.

In 1971, Bob bought a half-ownership in the Virginia Squires American Basketball Association franchise — as a tax shelter on the advice of a Philadelphia attorney. He attended one game.

After he sold his interest in the Squires in 1973, Bob made a succession of unsuccessful bids for prominent sports franchises, partnering with some of the biggest names in local sports, including John Kent Cooke and Lerner.

Charlie teamed with Bob in an unsuccessful attempt to buy the Philadelphia Eagles and the Redskins.

He offered to buy the Senators from real estate developer Bob Short in 1972 for $10 million, but Short took the team to Texas instead, where it became the Rangers.

Bob Schattner and fellow investors tried to buy the San Diego Padres in 1973 for $12 million before McDonald’s founder Ray Kroc snatched up the team at the last minute.

He, Charlie Bresler and Lerner tried to buy the Eagles in 1985, but again lost out, this time to a Florida car dealer. He tried to buy the rights to a National League baseball expansion franchise in the late 1980s, but the league declined to pick Washington. He was even part of a group that briefly negotiated to buy the Baltimore Ravens.

When Cooke got caught in a bidding war for the Redskins with current owner Daniel Snyder, Bob was in for a big pile. But it wasn’t meant to be.

“Always the bridesmaid and never the bride,” Phyllis Bresler recalled in her memorial.

Bob’s late wife, Kay Ferrell, was a Washington journalist and radio talk-show host. She died several years ago. Bob had two sons who were not involved in business.

He gave tens of millions to charity. He was a big benefactor of the University of Pennsylvania Dental School, from which he graduated at age 23 in 1948. There is a building at Penn named for Bob. There was a Penn contingent at his service, including the dental school’s dean. He gave millions to Washington’s Jewish Primary Day School.

Bob Sievers also spoke at the service. He met Bob in 1995 when he was hired to be controller of a bacteria-killing company Bob had founded, called Sporicidin.

Sievers will oversee the Schattner Foundation. Robert T. Schattner — Bob’s nephew — also will be on the board of directors with Sid Bresler, who is Phyllis’s husband and Charlie’s son.

Sievers recalled some of Bob’s Borscht Belt lines, which no doubt began when the 14-year-old played drums for $3 a night with a band in the Catskills. My favorite: “I’m the boss, you’re nothing. So I’m the boss of nothing.”

Sievers finished with the description next to Bob’s picture in the Penn Dental School yearbook:

“A prodigious operator of no low degree, constantly on the job achieving his purpose and goal in his own quiet fashion. Bob’s achievements in the field of dentistry are equaled only by his adaptability in music — the Gene Krupa of our class. Bob will undoubtedly go a long way in his chosen profession.”

I would say so.