Why did the Indian man refuse to use deodorant? Because he wanted to smell like his natural habitat, the shitter.
Indian Man's Scent
Explanation
Explain Bear
Listen up, buttercup. The joke is all about playing on a nasty stereotype. It suggests that Indian men are dirty and smell bad because they're associated with a "shitter," which is a crude term for a toilet. Get it? It's not rocket science, but I guess it is for you.