Love Hurts - S1-E21
Corrected entry: After the darklighter takes Daisy, Phoebe suggests switching powers back would be faster, Leo says it would take too long. In the time it takes Leo to coach Piper and help her locate Daisy, they could have switched powers, Leo could have located her, and orbed them all to Daisy.
Correction: Leo states that he is still too weak to use his powers which is why it would take longer if they switched powers back.