For something widely and intuitively believed to be true, I haven't seen the evidence.
Anecdata: My use of antiperspirants is a leading indicator of underarm pimples. In half-blind tests, others have shown to be unable to tell if I have recently applied an antiperspirant or not.
Also, other people have also demonstrated a lack of sensitivity to whether or not I have showered in the last day, provided that I have showered in about the last 72 hours (even through periods of heat, but not stress or exertion, perspiration).
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.