code:

on *:text:!massdevoice*:#: {
  if (( $nick isop $chan || $nick ishop $chan )) {
    var %Devoice.intVoices = $Nick(#,0,v)
    While (%Devoice.intVoices != 0) { 
      mode # -v $nick(#,%Devoice.intVoices,v)
      dec %Devoice.intVoices 
    }
  }
}