It works for me!!
I've been doing this for a while & it has lightened my underarms considerably by the first week, but hasn't gotten rid of the problem completely. Most likely I have an allergy or sensitivity to an ingredient in my deodorant & everyone else should take that into consideration if you have this issue too.
I started using the arm and hammer yellow deodorant about 6 months ago(only like $2.50 at Walmart) & I can honestly say my underarms look so much better. deodorant lasts and it helps the appearance!