I was (am) a long time sufferer of OCD, from about 12 to 32, mainly because I was unaware that was what I was dealing with, since I had a "pure o" type, where the compulsions were not so obvious and outward as cleaning/washing. Instead there was a lot of internalised mental rituals and checking like processes.
What finally let me beat it was:
- Finding a good support group (I used OCD Action's online groups). This was more about hearing from other people going through the same thing and feeling less alone to me
- Saving up to pay out of pocket for someone who specialised in ERP therapy
- Finally being sick enough of it to save up and join a support group
The last bit is the step that gets forgetten about often. OCD will really do everything it can to perpetuate itself and convince you that your compulsions are the only thing that can give you certainty and quell the torturous mental/emotional state you are forced into against your will. It took me two decades to get to that point by myself without help and just bottling it up. But someone who isn't ready to get better and isn't sick of their suffering yet will not be able to put in the hard effort it takes to get better. Because it is hard work. Absolutely worth it in every way, but brutal and exhausting.
On "enabling": this is poor word choice, but it is not completely wrong. The way to beat OCD is to stop engaging in compulsions: checking, washing, reassurace-seeking. Even better is to do the opposite of what the OCD tells you. Any serious resource will tell you this, instead of saying to give in and find ways to schedule or keep compulsions "controlled" as this is not possible. But, at the same time, you can't cold turkey it. You will fail if you simply try to stop everything. ERP therapy works by starting with very low-level panic-inducing scenarios and just letting yourself be uncomfortable, but then learning to trust the discomfort will leave on its own without compulsions. Very distressing and horrible for the first times you do it, which is why you need to start small and work up. This is also why it is much easier with a therapist who can monitor you and keep it at a workable intensity, as it can be easy to overdo it and end up in a one step forward but two steps back situation.
Here is a link for OCD action, they also have support groups for parents of sufferers, which I have not attended, but given how good their other support groups were and how serious they are about training the moderators, I wouldn't hestitate to reccomend them:
https://ocdaction.org.uk/online-support-groups/
I would reccomend you try to get your son to join one and listen. There is no need to talk. When they call on you, you can refuse and say you would rather listen. Any more advice on what to do, is not something you should be taking from online, but from professionals or OCD interest-groups who are up to date on the most effective treatment.
I will end with this though: despite OCD being in the WHO's top 10 most debilitating illnesses, it is very treatable. It actually remains one of the mental-health conditions we are most able to treat through ERP therapy. So there is hope, and you should keep this hope in mind.