It might be a dumb question but I don’t want to risk fucking him up somehow—what I’m most worried about is his stuffing getting mildew-y or otherwise borked. I’m pretty sure, almost certain actually, he’s polyester inside. Do I just dunk him in some soapy water, scrub him, and leave him in the sun for a while? Can I throw him in the washer next time I do laundry? He’d fucking love that.
Warm soapy water, hand wash, thorough drying in the air but out of direct sun.
Probably you could throw him in a laundry machine, but maybe use one of those laundry bags that are used to protect delicates like bras.
Use a cold wash, like 30C or whatever that is F, the coldest setting the machine has that isn’t literally just cold. Detergent requires some heat to activate but typically 30C is sufficient and you want to be at that minimum to be safe.
Hand washing in water that is warm like a gentle bath is likely best.
Then the key thing is really letting him dry. Thorough drying. Don’t put him in direct sunlight.
Do NOT use fabric softener.
Do NOT wring him dry. Just let him air dry.