Script goes in your mirc Remotes - (Alt-R)
I added a flood control to prevent you from being flooded. People can only slap you once every 8 seconds.
Code:
on $*:action:$(/(slaps? \Q $+ $me $+ \E)/iS):*: {
  if (!$hget(fc,$wildsite)) { hinc -mz fc $wildsite 8
    describe $iif(#,#,$nick) slaps $nick back with a large trout!
  }
}
Now it's recommendable to be used without the worry of floods.