No idea about the efficacy of DIM etc. mate but there is a prescription medication that has been clinically proven to reduce the amount of sex hormone binding globulin, thereby elevating free testosterone. It's Andriol (Restandol in the UK). It's Organons oral testosterone undecanoate - yep the little red rugby balls that everyone loves to hate. Not great for building mass etc. but it does reduce SHBG, causing an improvement in the ratio of free to toal testosterone. I may have the refernces/papers somewhere if you need 'em.
Cheers mate.
Cheers mate.