What would you do if a scraggly homeless person knocked on your door, and all he asked was for a sandwich, a bottle of water, a bath, and perhaps a beard trim?
I've actually skipped work just to help a homeless guy get his beard trimmed. Bought him pizza too. Kinda hard to get anywhere in life when you look like shit.
Be kind to the homeless, they just need a helping hand here and there.
I'd offer them the hose and privacy of the backyard at least. They could even use the warm collected rainwater if they wanted, I just would also get in trouble with my housemates if I did that.
Totally understandable, every situation is different. But what if you made a compromise, especially given the hotter than average weather lately, and gave the person a splash of shampoo and let him/her wash their hair with your garden hose in the back yard or something?