if you are going to go the route of doing on :text::#:{ then move the flood control under the if ($strip($1) = !time) cuz if you don't it triggers the flood control when ever someone types anything. or do it like this whatever...

on *:text:*:#: {
  if ($strip($1) = !time && !%t) {
    inc -u5 %t
    msg # The time here is $time(HH:nn:ss)
  }
}