For spoiler reasons I won't go into, my house Hjerim is awash with blood, skulls etc. I missed the option to "clean up the house" (the usual buggy standard, I see), and now it's not available. I don't have a save game I can revert to.

Am I just stuck with this charnal house, or is there some way I can fix this? Console command? Hire cleaner? Summon bleach?

Help and/or comiserations appreciated.

Looks like you need to activate the Janitors Guild questline.