The point of dt is to handle different framerates at the same real-world speed.
If something already uses seconds instead of frames, e.g. "Wait X seconds", "Every X seconds" etc, then it already works at the same real-world speed, because 1 second is still 1 second regardless of your framerate. So if you add dt it is simply wrong.
I think asking this question is a sign you don't quite understand what dt is for yet...