I'm sure you could try, but have you tried baby powder or a Gold Bond foot powder? Those products are probably better suited than underarm deodorant. I'm sure it boils down to a simple matter of preference, but any powder should do the trick. Baby Powder in shoes has always been a good quick remedy to shoe odor, so I'm sure the powder would absorb any wetness and the scent is delicate enough to not become obvious.
I know lots of people who use anti perspirant on their feet with good results. For some it doesn't work at all. My husband used to have a foot odor problem and what worked for him was sprinkling a little baking soda in his shoes. I've also heard good things about Avon's foot products.