Hello THEQ: I see this is your first post here on PC. So... welcome to PsychCentral! I hope you find the time you spend here to be of benefit.

I'm sorry I don't believe I am going to be able to offer you much insight into why the individual you're working with is doing what he's doing. Actually I have a rather long history of working with people who have development disabilities. But I don't know as that is going to be of any consequence here.

From what I understand of ODD, how this individual is acting is in accordance with what would be expected of a person who has that diagnosis. Why he is doing the specific things he is doing is something I could not say. What I can say, I guess, is that there are fetishes people develop around these sorts of things, including such things as wearing & using diapers for example. Perhaps what the individual you're working with has would be considered some sort of fetish. This is something that would really have to be identified by a qualified psychologist I would guess.

Fetishes are notoriously difficult to break. And the general consensus of opinion seems to be that rather than trying to do so, what is best is to simply find ways to indulge the fetish in some safe manner. So, from that perspective, it may be that the best you can do is to try to find ways to help the person you're working with learn ways of indulging in his fetish (if that is in fact what it is) in as safe & hygienic a way as possible. At least this is my thinking with regard to your post.

Here are links to a couple of articles, from PsychCentral's archives, on the subject of ODD:

https://psychcentral.com/disorders/o...rder-symptoms/

https://psychcentral.com/disorders/o...der-treatment/

Good luck!