I have a feeling that there's a more permanent solution being worked on to the whole cleaning and mud creep problem. In the mean time I was brainstorming on how to deal with my above-ground fortress that's now mostly covered in blood, from a single kobold kill a few seasons back.
Anyhow, the idea goes as follows, rate the blood/mud/vomit the same way water depth is handled, some sort of ranking from 1-3 say. A 3/3 tile, say a "pool" of blood can be be spread to surrounding tiles as a 2/3 depth say a "splash" of blood. Then if someone walks on the 2/3 tile they can spread it as a 1/3 "smear" of blood.
At the least, this will prevent a single corpse from causing an entire fortress to be painted red. I mean, at this point that kobold probably had a dozen gallons of blood in him to be able to cause this much scarlet spread.
Having a multiple strength rating for "mess intensity" could allow dwarves to clean up small messes quickly, and pools of filth will require a bit more work. Then maybe expand it so that mud will progressively dry out from 3/3 to 1/3, which will mean you'll need to replenish it using irrigation systems, something that many people I think have complained about. It was a bit frustrating making an elaborate flood gate system, only to realize that it only has to be used once.