Removing "dead" users

has anybody written a tool to delete users, who are not referenced by
any ticket?
i’ve marked unnecessary tickets as dead, and told rt2-to-rt3 script to
skip them in export. so i have an rt3 install with 10 000 tickets and 30
000 users…

Alek Cesarz : NOD manager : ALEK1-RIPE
+48 22 860 69 60 : Crowley Data Poland