You need to kill the bacteria which causes the smell not the actual sweating.

After your shower try wiping your pits with straight white vinegar. It can be a bit stingy, especially if you have just shaved.
Once it dries the vinegar smell will disappear and then try applying your deodarant.

I used Mitchem but I find I have to change every couple of months as I build an immunity to it but also doing this vinegar thing every week or so (whenever its hot and lots of sweating in happening) certainly helps me. I also use a anti perspir
ant spray on top of my roll on just to be on the safe side.