What if the friend had been doing his wash & decided to toss in the stinky gym clothes & something in the wash bled all over your clothes or his dryer got too hot & burned your clothes? Would he still owe you reimbursement? In your mind, probably yes.
It's true that no good deed goes unpunished. I think it was terrible to ask for money & it was even worse to have your conversation on your porch & not let him into your house. The way you treat each other makes it clear that this was not merely a platonic friendship. I think numbers is right & there was something else going on.