It sounds like you handled it really well.
We went through this when difficult child 1 broke up with his first girlfriend when he was 15. He stopped looking after himself, would wear dirty, crumpled clothes and not use deordorant. Let his fingernails grow to Howard Hughes proportions. I had to threaten to wash his hair for him, threaten to hold him down and cut his nails for him. If I raided his room to wash his clothes and change his bedding, he got upset with me because even if I put them all back dry at the end of the day before he got home, he couldn't sleep properly because they didn't feel or smell right to him.
I finally said to him (because he was 15) that if he didn't start adapting to this necessary change, I would go into the bathroom with him and I'd bathe him and wash his hair. At that time he also stank because of encopresis, I had to keep reminding him to go to the toilet. He would hold on for so long (a week or more) that the impurities would be coming out his pores and be on his breath.
A suggestion - boys stink, especially in puberty. Yours isn't there yet, but with no perfumes, any smells will not be masked so you need to work extra hard.
So a vital item to have in the laundry - a mist spray bottle filled with white vinegar. Spray it onto any garment that is affected with protein-based smells or stains (urine, BO, fecal stains or smells). Do it as soon as you put that item in the laundry, it won't matter if it dries on before it gets washed. Even better - train the kids to mist their own clothing. If it's really bad, you then put it to soak in warm water (blood-heat) and enzyme pre-soak, overnight. Then wash. It should eliminate any smells.
Find an essential oil you can cope with, and use it to add to the final wash. Alternatively, put a drop onto a swatch of cloth and put it into the washing machine. It should provide an alternative smell. But only if there is something that you can tolerate.
Teeth - you can get tooth powder, you can even make your own. I'll go digging for recipes. Sodium bicarbonate is a good substitute. So is salt. You just dip the toothbrush in salt, and scrub. Rinse thoroughly and don't swallow any of it, or you will get VERY thirsty!
Shari, you are doing the best you can, probably better than a lot of others would do under the same circumstances.
Hang in there.
Marg