I was diagnosed autistic in the 1970s as a child, but more recently with ASD and OCD. The OCD isn't specific to washing however, although I was over the top when I was a lot younger, particularly when I suffered with acne which I did become extremely obsessed about, I'd spend hours cursing in front of the mirror and I hated going out to the extreme even when I had 1 visible spot on my face, I think many young people go through this, but for myself I think it was blown up out of all proportion where it would be on my mind throughout every waking minute of the day, even when focusing on my special interest and for a while it ruined my life. I get obsessed with things far too easily and I find it impossible to stop myself sometimes, I have a certain level of control, although the anxiety side of it constantly effects my life. I am always waiting for something bad I can't cope with to happen that I try to obsessively avoid and I'm always over hooked on something that I'm very anxious about that I worry about losing or changing, in a word it is "hell" and I get very little support or understanding which upsets me because many NTs seem to brush it aside as nothing, but I refuse to take prescribed drugs to block it which have only made matters much worse in the past.
There seems to be another part to OCD, that's if it is even related, but here goes. Even with my cat I find myself going through more an more complex rituals before I let her out if I don't force myself to stop, E.g. I will have to say specific words in order first, because illogically my brain starts to think that if I don't something might happen to her this time and I worry greatly when she's out every time, in fact now most of the time I'm actually out with her watching for ages and neighbours seem to take the "p**s" out of me for it. I have seen this much worse in my brother Daniel who is on the very low functioning part of the spectrum, E.g. he can't count to 5 or tell the time. He goes through very complex sequences where he makes different motor like noises in order and moves his hands in a very specific way with the exact sequence which takes a few minutes each time, if he is interrupted he gets extremely upset and he has to start the entire sequence all over again, if this happens more than once he can go into a full meltdown where he throws himself on the floor in a severely upset state, so it's certainly best to let him get on with it without even talking to him. He does this many times a day. Unfortunately he is unable to recognise that these compulsions are illogical and attempt to override them before they get completely out of hand. I'd actually be really interested as to whether anyone can relate to anything like this?