guest off

on @*:join:#:{
if ($regex($nick,/^guest\d+/i)) { ban -k $chan $nick 3 No guests? }
}

guest end

alias guest {
if ($regex($1,/^(?:on|off)$/)) { $iif($2 == on,.enable,.disable) #guest | echo -ag Guest is now $2 $+ . }
}
or you could just ban guest* pointless script