Each of my kids was different with this. Wiz would fight tooth and nail not to shower. Partly sensory issues, partly because we wanted him to do it. This started about age 4 or 5. Before that we couldn't keep him OUT of the tub/shower. It wasn't unusual for him to take a bath, then if one of us was in the shower and the other one took their attention off him for 2 seconds he was in the shower with us, getting all sudsed up again. Since he didn't have eczema it was no big deal. But when he started balking, boy did he balk.
Sensory issues were part of it. Also he was very much into doing whatever we didn't want him to do. By the time thank you could talk, thank you would go to the bathroom door and yell in "Wash your stinky bottom" and "Use soap" and other things. NOT prompted by us, but he would hear us coaching Wiz (husband from inside the bathroom or me from outside the door as Wiz was 8 or 9 by this time). By the time Wiz went to the psychiatric hospital at age 12 he was worse than ever about bathing/teeth/hair washing/deodorant/etc... At the psychiatric hospital they would have a male staff member stand outside the shower to check them. If they were not clean they had to go right back in and do it again, over and over until they actually got clean.
At one point Wiz led his room mate and 2 other boys into a rebellion against the hygiene standards. So the boys were "schooled" as to how to clean themselves. They got lessons, had to write out the steps to showering, hair washing, deodorant, tooth care (including flossing), and getting their clothes into the dirty laundry. Even hwo to hand up towels. Then they had to DO it. And with this a male staff member stood in the bathroom on the other side of the shower curtain to check to see if they were soaping hair (they had to stick just their heads out to show the suds, then to show tehy had rinsed completely). Staff even made marks on their arms and legs and feet with an eye pencil that would wash off with soap but not just rinse off. This way after the shower they could check to see that they HAD soaped. (I thought that was GENIUS - a way to check that they were washing with-o actually watching them in the shower - before this the boys had to wear swim suits to shower so that they could be completely monitored).When a staff member had to be in the bathroom for this, parents had to sign a consent and they used a special bathroom with a camera set up so that it watched the staff and had NO view of the child. This was to protect the child from abuse and the staff from false accusations. Parents got to see this set-up and see the tapes (if you wanted to see the tapes). We saw the set up BEFORE they did this with our child.
With thank you we have sensory issues with hair washing and bathing. If I am suspicious that he skipped the soap I lick his arm. If it is salty he goes back in. By this age (9) we don't have too much problem with washing his body. I just make sure he has teh body wash he likes (lavendar baby wash) and it isn't a problem. He even uses deodorant. He sniffed his armpit one day last summer and gagged. He came to me BEGGING for antiperspirant. Said he would sneak and use his dad's or Jessie's if i didn't get him his own. NOT A problem, LOL!!! I hadn't even noticed a problem yet. (FInally a time sensory issues came in handy, LOL!!!).
Hair washing is a whole other issue with thank you. He has thick, thick curly hair. More wavy than curly, but very very very thick and coarse. It actually HURTS him to just wash it with shampoo. And I had a tough time finding a product with conditioner and shampoo in it that he could tolerate the scent of. For about 5 years I actually bought shampoo and conditioner in the same scent and mixed them together in a bowl, then put them into empty pump bottles (he had a hard time with the shampoo bottles). I found this way it hurt him less to have his hair washed. Right now he is using the Suave Men's 2 in 1 conditioning shampoo and conditioner. It is less of a hassle for me, though he told me tonight that it still pulls more than he likes.
Looks like I will be mixing them together again. I actually used a little more conditioner than shampoo when I mixed them. Just had too.
for teeth, well, thank you has always LOVED to brush if I had toothpaste that wasn't Mint. He hates anything Mint. Also hates bubble gum anything, so for a while it was hard to find something that worked. His all time favorite is the Shrek toothpaste that looks like snot. Gross looking, but it gets the job done.
With Jess, she LOVES certain flavors of toothpaste. So I buy those for her. And the electric toothbrush is great for her. So is the ToothTunes brush. We have used various ones over the years.
Wiz never did get braces because I saw no reason to put braces on teeth he flat out refused to brush. Ever. It was a major battle every time, no matter what toothbrush, toothpaste or incentive we used. Even the psychiatric hospital had HUGE battles over that. It may be sensory, it may not. I have no idea. But braces would have been a colossal disaster and waste of $$ that we couldn't afford to waste. If he wants his teeth straightened, he can earn the $$ and pay for it himself. The psychiatrists we have had, and teh tdocs have all backed us up on this. Even when a DHS caseworker tried to use that as neglect, the "experts" backed us up and so did the psychiatric hospital and the dentist!
It is different with every kid. You just have to work to find a key. I have found that asking WHY something is refused can be helpful. But it isn't always helpful.