Dude, dont try to do anything with it at home. Your chances of further screwing it up are much greater than success. My suggestion (if you have some time and a little money) is to send it out to Rave fabricare in Arizona (http://www.ravefabricare.com/true-quality-cleaning/2012/3/16/rescuing-a-dairy-product-saturated-suit-used-in-a-commercial.aspx).
It isnt cheap but after a garment has already been dry cleaned and the stain wasnt taken out, it could have set in the stain. That is why i would send it to the best cleaner in the country. Oh and try to get your money back from the previous cleaner if you can.
having jessie do a test for them, got to check out the web commercial later