I take cloth with me to my parents and my FIL's with no trouble. I take our own detergent and nappy bags, and each 2nd night (last time we were at my parents as there for 2 wks) just stuck a nappy wash on once Faye had gone to bed, they have huge long radiators that are on low all the time so everything tended to be dry the next morning
My FIL was a bit of a funny one, he doesn't object to cloth but hes as precious about his washing machine as I am about her nappies! So we had a bit of a stand off in the kitchen - he did let me put them in the machine when he realised he might touch a wet one but wouldn't let me switch it on, so I had to instruct him over his shoulder and remind him twice not to add conditioner
We had a really bad poo though and it was everywhere, even escaped into the wrap
I had to use his bath to get the worst off and then out of paranoia (cause I didn't dare tell him) used half a bottle of Ciff to clean it afterwards!!