Another suggestion
Code:
On ^*:OPEN:?:*: {
  if ( $nick == ispukikoy ) && ( $1 isin on off ) set %pmb $iif($1 == on,1,0)
  if ( %pmb ) halt
}


You pm the bot with "on" to turn on the PM blocker then "off" to turn it off.
* Only your nick can turn it on/off.

If you have a plastic floor runner over your tiles, then you're one Hella Pinoy!