Oooooh, this was hilarious. As they said above, leave it to the twins to invent something like that... and of course it would be a business huge success. I liked it that you stressed how the pills probably worked, taken correctly - the twins are indeed gifted wizards.
I laughed a lot at Susan's reactions. When she says that against Lavender, you'd think she was the one under a Tongue-Unleashing Charm or something, just being unable to repress her own words and stay professional. Good for her that Harry is even more embarrassed than she is. And I laughed out loud at the idea that in the magical world, floors can swallow people... but never at the right time. Also liked how he asks her out. Thanks!