Not all products break down at the same rate. Factors that affect how quickly toilet paper "dissolves" include:
Dissolution speed varies by product type and environmental factors: Does Toilet Paper Dissolve? - Roto-Rooter does toilet paper dissolve in water
Single-ply paper typically disintegrates much faster than plush, multi-layered (3-ply or 4-ply) varieties, which can sometimes trap air and float or remain bulky. Not all products break down at the same rate
The longer paper sits in water, the more it softens, which is why most plumbers recommend waiting a few minutes before trying to flush a particularly large amount. Why Paper Towels and Tissues are Different multi-layered (3-ply or 4-ply) varieties
Manufacturers use short, absorbent cellulose fibers that hold together when dry but lose their bond once saturated with water .