Can drain cleaners (Draino, Liquid-Plumr, etc) cause a huge brick-like occlusion of your shower drain?”
Thus, one must keep water flowing thru the pipes. Fortunately for us, the drains that clog are the oft-used toilet and shower. I’ve never used those things, so I am saying “in theory.” I have had experience with water pressure both clearing a drain to the sewer and merely sending the plug farther down the pipe where it really parks. The trick will be finding out the chemistry of those drain cleaners you mention and what happens to the residue after 24-48 hours. Or hot water down the drain for an hour.
