This sensory-deprivation floating tank sounds like something I could make at home, using my accidental stockpile of Epsom salts. (I tend to buy supplies, then come home and discover I’ve already bought some. Ask Galen about the quantities of cornmeal we amass before I remember to make polenta.)
Why have I never thought to make a super-floaty bath? Saturating a bath with 10 pounds of Epsom salts would be a good way to use up that part of my craft stash.
Having made several small projects without putting a noticeable dent in the stash, I’m remembering that my original intention with the stash manifesto was to make huge craft projects. Things you can only accomplish with ten pounds of origami paper, not small things here and there. Floating tank, several pints of Epsom salts… I think it counts.