How do I Mass Delete over 45k Inactive Users?

[K-fab]

New forum owner here (took over an existing site).

I just pruned out a bunch on v3.7.1. Did a search on users that haven't posted in "x" time, had less than 1 post, haven't been on the site for six months, etc.. It came up with 51K+ non-users (mainly spammers - they all need to be beaten about the shins with a stick).

It removes 999 at a time and I clicked 52 times. Pain, but works. Once I got the place clean, I've been staying on top of it.

I check my new registrations every morning while I sit and drink my coffee. Usually it's about 20 new users and of that only three or four will be legit.

I cross reference each IP address (google ip spam, then paste each IP addy in the search window) and if it comes up on the spam list, I delete that member and block the IP addy.
User CP
vBulletin Options
User Banning Options
There's a window in there to put IP addy's and it will block out those from coming to the site.

Seems to work pretty well and doesn't take long.

To make it go faster, I open each new registration in a new tab instead of clicking on that member and having to go through the search again and again.

I cut/paste the IP in the spam check and if it comes up on any sort of list, I just delete the user and add the IP to the block list. If it comes up legit, I approve the registration. Close each user tab after you decide to keep or delete.