Dark underarms. hydroquinone did not work. What are my options? (Photo)

I've been off of antiperspirant for 2 years now after getting miraDry. Now I've been trying to treat my dark underarms. I was prescribed 4% hydroquinone that I used twice a day but it worsened the darkening even after exfoliating three times a week. I stopped using Obagi and started using a moisturizer with 2% salicylic acid. It seemed to quickly lighten my underarms for some weird reason. I don't know if it is the salicylic. Now my question is... What other underarm lightening treatments can I get?