Every day in a white-walled room in Miamiville, Ohio, a half dozen middle-age women in lab coats line up with noses poised and clipboards at the ready. Their mission: to rate the efficiency of deodorants, antiperspirants, mouthwashes and feminine hygiene sprays by sniffing in places that would give 99.9 percent of us olfactory arrest.

Led by Thelma Williams, a spry, 59-year-old veteran sniffer, the odor testers of Hill Top Research, Inc., routinely snort the emanations of scores of armpits, feet and morning mouths, noting their reactions on a 1 (good) to 10 (fatal) scale. Results, before and after use of a particular product, are then sent to such clients as Procter & Gamble, Bristol-Myers and Lever Brothers. “It’s amazing how many of these large companies can’t find anybody to sniff an armpit,” says Williams. Adds the mother of five and grandmother of eight: “When you’ve rinsed out diapers or cleaned up after a child who is sick, this is nothing.”

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Williams and her crew work with about 500 paid test subjects, drawn from the farms and small towns northeast of Cincinnati. For deodorant and antiperspirant sampling, the guinea pigs agree to avoid using such products and bathe with unscented soap for 10 days before testing. Alcohol is forbidden on the night before a test because it affects how a person smells. “We need people with a somewhat bad odor in order to figure out if the product reduces it,” Williams explains, noting that only those whose natural rankness ranks between 4 and 8 are accepted for testing.

In a typical series of tests, sniffing is done at regular intervals for one week in a room that is continually flushed with fresh air. After the test subjects doff their unscented, laundered T-shirts (women, tested separately, are required to wear bras or halter-tops), the judges take short, repeated “bunny sniffs,” sampling for a short, pure burst of “malodor,” not the distinct scent everyone seems to have. Later, after using the product in question, the subjects are sniffed again to see if their odor level has dropped to the two-or-less rating that manufacturers desire. In the case of antiperspirants, test subjects sweat out the product trials in a specially designed “hot room” where the temperature is 100° F. To keep the perspiration level from being skewed by emotional factors, panelists are forbidden to play cards or discuss religion or politics. But if a client firm requests emotionally engendered sweat, a psychologist is brought in to stir debate among the sweatees.

In addition to smelling “axillary vaults”—Hill Top’s fancy term for armpits—judges also sample mouth odor. Starting at 4:30 a.m., these exams require pristine morning mouths, unadulterated by coffee or cigarettes, and are conducted with testers taking whiffs through a cardboard tube. For feminine hygiene sprays panelists are cloaked and examined quickly in curtained cubicles. “None of us minds doing this,” says Williams, “but we don’t want to embarrass them.”

Armpit tests are the most common, with between 50 and 90 persons daily raising a salute for science. They are paid up to $65 per week. “This just gives me something to do—plus I make money,” says Pete Hupp, a retired maintenance foreman and two-year odor-testing veteran. Williams generally discourages raunchy BO jokes, but admits she was amused when one man’s raised arm revealed a happy colony of plastic worms.