I use this:
https://vborg.vbsupport.ru/showthrea...highlight=spam
Over the past month my board was overrun with spam bots. That hack will catch all the spam - drop in the moderators queue for approval - and it never hits my board. At that point I can delete the accounts when I have the time.
As for the others.... no point in trying to block ips. I just block e-mail addresses like @mail.ru and others which obviously don't belong. My spam has dropped by at least 98%.