'Be Brave and Go Get Your Legs Waxed' would be a variant on “Be Brave and Shave” (like at the Westover Market in Arlington Va.). The latter is often a fundraiser for cancer and usually applies to scalps only (mostly men). It’s a rather obvious reference to hair loss from chemotherapy (or maybe even a bone marrow transplant). Some hair loss has been reported from Long Covid (and in women). (It also happens to Matt Damon's character when he does a "go get small" in "Downsizing".)
Sacrifice of body hair in men is much edgier, but there are some videos on YouTube that show this as fundraisers.
Here is a typical one from England, Scott Parker, “Waxing My Legs for Cancer”, a little over two minutes, partly in black and white, in the style of a horror movie. He resists.
Hair would take longer to grow back after waxing or chemical epilation than from shaving. Image someone doing this with a laser to make it a permanent sacrifice.
Remember the “Man O Lantern” from “The 40 Year Old Virgin”?
A cyclist waxes his legs for a charity bike race in another video.
Remember that in the first season of Donald Trump’s Apprentice, Troy McClain got his legs waxed and “took one for the team” and that got mentioned in Donald’s “How to Get Rich” (before going bald in the legs anyway). In the 1980s there was an issue of "Christopher Street" titled "When Ronnie took his pants off", discussing Reagan's movie "John Loves Mary": "However ladylike his gams, they prove the existence of heterosexuality".
Remember the Tribunals after two weeks of class at William and Mary in September 1061 that I skipped out on. Rituals can be exciting.