Since I was thinking about Unfuck Your Habitat today, anyway, I decided to finally post these pictures I've been sitting on for a few weeks.
I sincerely hope this is the nastiest bathtub you see today. It was getting a little grungy anyway, but then the drain clogged and every last bit of dirt and soap scum decided to try to take up permanent residence.
The first picture is my cat listening to the drain volcano fizzing down the pipes. He got in there while I went to fetch my other tools, and of course I snapped a photo before removing him and cleaning his paws.
One Zip-It later, I was ready to use the tools you see in the second photo. I plugged the tub, then put in some very hot water, just a touch of soap (the right-most bottle) to remove the crud, and vinegar and lemon juice to reduce hard-water buildup and make a nice clean smell.
Then I went to town with my trusty scrubby brush, which is much easier on my body than using a sponge. Up and down and all around until I achieved the improved tub in the last picture. You can still see some discoloration, which I did end up having to sponge away later. For that first day, though, the tub in picture three looked like VICTORY.