Any "fluffy" TP will clog more than a standard, e.g. ScotTissue, TP. A huge added plus for the thinner firmer Scott type TP's is that for those of us who have hair around our bungholes, the Scott type TP's will be more resistant to leaving unsightly dingleberries and puffs of paper, a sure sign of not being "fresh" to those who may eyeball your bung in unexpected circumstances. In my Ultramax and my standard Gerber(both terrific flushers), the Kirkland equivalent of Scott, bough at Costco, never causes a clog. It's when I run out of TP and have to run out to the local 24 hour deli, and come back with some poofy TP with a fag name that I have to break out the plunger.