I only have a senior reamer, and I've discovered that several of my pipes have a slight taper to them that the senior is well suited to. You just twist a couple times, reduce the diameter slightly and repeat till you get to the bottom. It seems to me that that reamer is designed to leave a semi-conical cake at the bottom. Might not be a bad thing? I don't have enough build up on my pipes to know (at least not on the bottom!).