I think the OP wants to have users with powerful GPUs to bruteforce attack his wallet. But then there are no assurance that it contains enough bitcoin to fulfill such 10BTC payment he said. Also, there are a lot of factors to consider before cracking/bruteforcing a password such as its hash salt and the length of the password. Hence, better try to hire professional ethical hackers or just consult to them because even powerful GPUs cannot be successful with just forcing a hash without knowing its salt.