On fine days set up a tarp outside dor the kids to do arts and crafts instead of indoors.

I would definitely look at some activities outside they can do. If they have to play inside, making sure that everything is packed up after they use it before moving on to the next thing!

Play outside, and get over it. It is easy to clean once theyve left.

If you know they are coming plan specific activities for them to do, outside if possible lol and have a rule where everything must be tidied up before they start the next activity and also before they go home. So long as you are up front before they start something and they know what’s expected hopefully it will be easier.

My sister in laws kids are exactly the same.
When they come over they play outside and aren’t allowed in the house unless it’s to go to the toilet!
That way they can run around the yard and we’re not too bothered.

I’d get them to clean up after one activity before moving on to another activity.

Limit what they do, what they touch, what they eat and drink.

Maybe you could make it clear that in your house, your rules apply, and that includes cleaning up their own mess before they leave. That might (eventually) encourage them to make less mess in the first place.

Yes. I want some tips too. Great thread question

A conversation prior to any future play might be a good idea. Adults need to reinforce the rules of play and cleaning up and respect.

Rules and boundaries about play and cleaning up may be useful?

Encourage them to clean up after themselves. I always say to my kids ‘everyone start packing up the toys’ and hopefully your sisters kids will copy this behaviour
Also maybe just say something to your sister about it

I always made the kids play outside or they had to clean up any mess made before they left. Normally the Mum would do it for them but I refused to help hoping the Mum would stop. Since my kids always had to clean up if they went anywhere so I expected the same in return. Explain this to your sister and if this doesn’t work then restrict what they can play with and where. Hopefully your sister comes on board

I’ve always put a limit on how much gets taken/tipped out, otherwise it’s way too much mess to clean up later. I also say they have to clean that up before taking out the next lot of toys, and they also help clean up at the end of the day

Your house – your rules. I did get my kids and friends to make sure they would pack up just before being picked up. I was a little naughty too and would sometimes bake biscuits and tell them that they could have some if they packed up all toys/art & crafts stuff and cleaned up nice and tidy.