Drain's fixed!

My clogged shower drain is now fixed.

There's 2 plungers in my bathroom that were there when I moved in: a deep powerful-looking one, and cheap shallow one with a broader cover.

Since I suspected that the deep one would have the seal break sometimes when I plunged and thus it didn't plunge effectively, I used the shallow but broader one to plunge quite a bit when the drain was clogged.

After a while, vigorous shallow plunging caused whatever it was to flush down, and now my drain runs normal.

The bottom of the shower had a layer of grime on it from the dirty water that had been sitting there for a while, but after I took one shower, it all got rinsed away down the drain.