there is a big difference between cracking password (hash) and finding a private key of a given address (which is what BitCrack tries to do).
finding a hash of a password is very similar to finding the hash of a block (aka mining) and ASICs should be excellent in it (not bitcoin ASICs used in bitcoin mining but an ASIC devices designed to do this). but it still is going to be a lot more  complicated and possible impossible to do the later (finding the private key) using ASICs.