I hate deodorant.
I wash my armpits with surgical scrub (the chlorhexidine kind) for three days in a row, then go back to ordinary soap. The surgical scrub kills off the BO-causing bacteria and it takes weeks for them to recolonize. Until they do, I don't get smelly. Then I repeat the process. I imagine it wouldn't last as long if I bathed less often.
I'm a smelly person. If I don't do this, no deodorant works very well (they just feel nasty and smell bad on top of my own rankness) and I have to wash-cloth bathe myself in the bathroom at work mid-day and put on more deodorant, and it's terrible. When I do it, I don't need deodorant.
The same scrub is supposedly good for acne, but it'd probably be a bad idea to wash your whole body with the stuff, or to use it all the time.