Possible Clues:

• Coarse rug
• Does what you get from the chemist get one lying on the floor?
• Will the dope get rough underfoot?
• How does this sort of medicine get on the floor?
• Dirt initially sticking to carpet? Acquire protective floor covering
• Coarse floor covering
• Get hooked on it and get to put your foot down over it
• Does something so habit-forming get one on the floor?
• It may be its habit to get underfoot
• Hemp, perhaps, to become floor covering