What might work is to be selectively clean. For example, you can clean just one dish, one glass and set the table with dirty dishes for the rest. And when they look at you in disgust, not wanting to eat in a dirty dish, you can say "well, I assumed you didn't mind, since all the dishes were dirty and in the sink".

But to be fair, it might just be better to refuse to live with people who can't clean after themselves. Yes, that includes boyfriends. After all, if they want to live with you, the least they should do is respect some basic higiene levels.

Being bold also helps. I mean, saying things like "I don't like going to your place because it is dirty" might hurt him in the short term, but it is a truth that he needs to learn. For his own good.