The Centennial kitchen line problem
Cooking grease leaves the pan as a liquid and cools into a solid somewhere under the slab. Over a few years it narrows a two-inch branch line to the width of a pencil, and then one holiday dinner finishes the job.
Why wipes never break down
Toilet paper disintegrates in seconds. Wipes are fabric. They catch on any imperfection in the line, then collect every wipe behind them until the pipe is packed solid.
Jetting versus cabling on a grease line
Cable bores a channel through grease and the channel closes again. Jetting emulsifies it and flushes it out, which is the only way to actually restore the pipe diameter.

