Do It Yourself

Trying to fix a slow bathtub drain.

It's got one of those flexible ribbed pipes that keeps holding onto everything, and whoever installed the bathtub had the amazing idea of fully encasing it in brick and large tiles, with no access left to replace the pipe. To add insult to injury, the pipe is attached to the bathtub by a single screw going through a metal strainer, so no way to properly shove in a pipe cleaner without it coming detached and falling under the bathtub... inside the encased part; even if I managed to fish it out afterwards, no way it's going to match the gasket again. The toilet is also so close to it, that even to try breaking the tile and brick to get to the pipe, one would have to remove the toilet first.

I've poured in some "gel drain cleaner", left it for a while, washed it out, and some plunger action seemed to move some stuff around, but it was still slow. Poured some caustic soda, which outgassed pretty nicely, and the plunger worked some more, but I'd say it's still less than 50% there.

I'm torn as to what to try next, whether some HCl, bleach, or sulfuric, but the strainer is metal and I don't want to make it look worse than it already does. Could try more of the gel and/or soda, but I think they might've already done all they were to do.