I read that and said to myself, "What???!!!" So I looked it up in the online slang dictionary. I'm filing their explanation of the "float" phrase under "Sounds like a bunch of made-up baloney."
Reading their fantasy explanation I'll be careful not to use the phrase (I don't recall using the phrase though have heard it often), but I think they just have very vivid (and prurient) imaginations to come up with that one.
The all-too-common phrase that makes me cringe is, "That s*cks!" I can't imagine a polite origin of that one, but I have even heard it from a couple of "trad" (???) women. Go figure.
Yeah. I always took it to mean "whatever works for you". I have never heard it being used in a vulgar way.