How about just playing the $50 on one side, and $50 on the other side (at another, reputable book) and continue playing your entire BetOnUSA stash (if you win) until you lose. Aportion of the free money ends up in your other account (reputable account that you know you can get at) minus the vig (times however many bets it took you to lose the BetOnUSA all-in bet).