First things first, let's get this straight: deodorant and antiperspirant are not the same thing. Deodorant merely covers up the smell, while an antiperspirant has a chemical configuration to reduce the source of the odor — sweating. To boost the power of your odor-blasting product, shave your underarms and wear deodorant to bed.
If you're a severe underarm sweater, consider Botox as a solution. The injections can paralyze the nerves that activate sweat glands, meaning you could be sweat free for longer periods of time.