He is old enough to wash his own clothes. If he doesn't, he will learn by natural consequences. His peers will point out that he smells bad.
My kids have been washing their own clothes, including my autistic son, since age twelve. I have had many problems with a few of my kids, but I did do some things right and they did have to be responsible for their own belongings as soon as they were able.
There is no reason for you to be parenting a grown or almost grown adult child. There are many good reasons why he should be forced to grown up himself.
You can't change anyone except yourself. Angsting over his behavior won't change it and won't help him or you. It is a lesson we all have to learn. It just causes ulcers, migraines, high blood pressure and misery...and our adult child remains the same as he was before until he decides/if he decides to change. It is 100% up to him. It is 0% up to you...or any of us.
Great job with your restraint. Overtalking causes more than 50% of our grief with our adult children who are good at manipulating us, pushing our buttons (especially our guilt buttons...they know what and where they are) and blaming us for their own bad behavior. I found it is best to stick to light topics, such as the weather, and listen to any nonsense difficult child is spewing rather than piping in my two cents. And if things get heated on his part, I get off the phone pronto. Why do the theatre at my age? I had it when my kids were small. In my world, peace rules/drama drools
You have to decide your priorities. At the same time you will come to see that no matter how much you talk to, push, get angry at, love on your grown kid...he is what he is and he will not change until/unless he wants to. Some of our difficult children truly think alternative lifestyles, such as homelessness, are just fine...and they'd love big contributions from Dad and Mom too because they also often don't want to work. And many take drugs. And they would love us to chime in the $$$ for "food" when they really mean drugs.
You will find your own path. We all do. But you will take your own path. Your son will take his. They won't be the same path.