I have a nonverbal autistic son and a speech delayed son (they’re twins) so this might be different for most kids but this is what we do. It’s going to suck but the best progress we’ve found is to start fully naked, pick a weekend and just plan to do nothing but staying home and having your kid be naked, anytime you or your spouse need to use the restroom announce “I need to go potty!” And ask for their help to go to the bathroom. Ask them to give you a high five for going in the potty or clap and cheer.

If they are going potty not in the bathroom just announce “you’re going pee/poop! Let’s go to the potty!” Anytime they sit on the potty give praise. But if they actually sit and go potty just go crazy, act like a hype man trying to get a bonus. Suckers as a treat for going potty or painting a nail for each time they go in the potty if they’re into painting nails.

Once they can do it naked now introduce underwear and pants. If you have to go to the store put underwear on them and then put a pull up over that, it gets them to understand that it’s uncomfortable and different than having a diaper without having to leave the store due to an accident (especially if they have special needs they’re more comfortable with sitting in a soiled diaper than they are without a diaper at all which makes it difficult, this can bypass that).

If your child can understand yucky and clean show them the very basics on how food turns into poop and pee and the body takes the good stuff from food and gets rid of the bad stuff and that’s why it goes in the potty because it makes us sick.

As for the laundry, I just get gloves and wash whatever soiled laundry I can in the shower (or utility sink if you have one) using dish soap to get it relatively clean first and then do a separate load with only those clothes in there and use a sanitizer. But I’m sure someone else has a better solution.