I took a mountaineering/backpacking class a century or so ago at Yosemite NP climbing school. Their moto was "Clear and Copious". They used to preach this all through the course. Especially at higher altitudes you need to drink copious amounts water because you don't feel your self sweat because it evaporates super fast the higher up you are. And if you are drinking enough your pee will be clear. The instructors said that clear is always a good measure of you proper fluid intake no matter were you are.
Don't laugh.... Here are the keys to not stinking:
1) drink lots of water
2) shower every morning and get yourself clean
3) wear 100% cotton shirts. "performance fabrics" might wick away sweat, but they don't breathe. They make you stink. So do wrinkle free shirts.
Do that and you don't need deodorant.