M.S.
It is deodorant stains, and I had the same problem in my clothes. I was not able to get them out, but I didn't try very hard. I too, switched deodorants and have not had a problem since. I've tried both the Secret and Dove (?) Clinical Strengths and neither compared to Certain Dri. With the first two, I wasn't able to go the few days between applications, where I could go up to 3 days without reapplying Certain Dri.
Sorry, I'm no help with the clothes. :{