BEIJING — Unilever brought its Rexona deodorant to China a decade ago, dreaming of a market with 2.6 billion armpits.

Wages were rising, consumers were spending and the run-up to the 2008 Beijing Olympics was making Chinese people feel more cosmopolitan. More of them, it stood to reason, would be open to a Western hygiene product.

“We had created established markets for Rexona from scratch in many countries, and we did not see any reason why we couldn’t do the same in China,” Frank Braeken, Unilever’s former China head, said by telephone from Dubai, where he now works as an investment consultant.

“We had an extremely ambitious plan at the time,” Mr. Braeken said.

But cultural differences and simple biology — scientists have shown that many East Asian people don’t have Westerners’ body odor issues — scotched those plans. Sales totaled only a fraction of the Chinese marketing budget for Rexona, Mr. Braeken said. Today, by some estimates, less than 10 percent of China’s population uses deodorant, and it can be hard to find outside major cities.