Oh jeeze, that sounds like such a mess! I'm so glad you found a solution, and it was very nice of you to share it here in case any of us run into the same attack.
Hey, you also might want to check out the vb4 Spam-O-Matic mod; definitely one of the best I've ever used for preventing spam registrations. A few still get through every now and then, so I'll have to go delete them to avoid becoming an e-Pharmacy