I don't go so far as to clip the dirty tip off a used PC, though I am known to be cheap, frugal and very obsessive about wasting not. In fact, I use the old PCs as fire starters for barbeque - throws off a great aroma. I'm a minority, on a different track than all the posters here, since I average maybe 3 cleanings per PC. I re-use pre-used PCs on the first swab, usually into the shank where things are tarrier. I also fold over the used PCs with dirty tips, twice in fact - that gives me more circumference to work with inside the mortise. Then I run clean (or at least cleaner) PCs through till one comes out more or less clean. I set each PC on a tray in order of use, and have 5 or 6 going. Estates, which I don't run through a retort, chew up a lot of PC usage, especially the first dozen bowls.
hp
les