Well you would still need some sort of timer that checks the variable every so often.
On the other hand you could change the time between checks with my script.
if ($nick == $me) .timerbans. $+ $scid($cid).network 0 300 check_bans $chan
Just change the 300 there to how many seconds between checks you'd like. The less time between checks the more this script could cause things to lag. I'd suggest setting it to 15 or 30 seconds and call that good enough.
