I feel your pain, I went away in august and through lack of other options got my daughter’s 18 year old friend to house/puppy/cat sit, he generally comes over to see dd quite a bit and the animals know him, and he’s usually pretty good at tidying up after himself. I did pay him (quite generously) for his services.
I made a point of tidying/cleaning before I left thinking that would encourage him to keep it like that, but no, the kitchen sides and all floors were grim, and there was shit splattered all over my toilet.
He also obviously didn’t bring enough/any socks for his stay, so he used mine! My socks are all arranged neatly in my drawer kondo-style, and there were several pairs of my white trainer socks just chucked on top of all the other socks when I came home, except they weren’t really white anymore and they were all crusty.
But most annoyingly, and this is a weird one - I sell books online and have about 3000 books in my loft, a lot of which are worth a fair bit of money. They are in boxes, arranged neatly so as not to damage them, and there is a system for where they are, although it might not look like it to the untrained eye. I didn’t go in the loft for a couple of weeks after I got back but when I did, I saw that many of the boxes of books were not as I left them, they’d been rummaged through and left in a right old mess, with paperbacks bent in half etc. I was freaked right out and thought I had some material for a woo thread, but then I thought I would message DD’s friend to see if it was him. He replied hours later saying “yes I did go up there, hope you don’t mind, I’d never been in a loft before and wanted to see what it was like” 😵💫😵💫😵💫