Some people are prone to heavy sweating, can't be stopped. The active ingredient in most deodorants is aluminium Chloride AlCl3 If you spray a spot on your arm you might see the fine white grains of it. Its a very cheap substance you can buy as a powder. Why not buy it in a packet and use it as a talc.
The "smell of deodorant is of little value though I loved Tabac because it lingered.
The way deodorant works is to soak up sweat. (The AlCl3 does). Sweat + hairs = the smell. Sweat + no hairs = no smell. So shaving armpits works Blondes tend to have less hair in armpits, luckily for them