Oooh don't jinx me. Still dealing with the "mini-chip-tuning" a-holes. Who are they?????
So, I blocked Russia and China (felt like I was playing a game of Risk), among a few other countries I know I'd never ship these here nutes to, removed open registration, and now I'm getting slammed with membership applications , lol. I feel your pain.
There is a solution, but I've been too lazy to do it: Install captcha and integrating it with a custom form, outside of the system registration system (drupal cms).
When I do actually do that, life should be a lot better, because I am about to launch a grow management system for my customers, and need to be able to scale easily. Hand picking registrants is FOR THE BIRDS.
Have you tried Captcha?