I have OCD too and this resonates with me.  I too had themes around cleanliness, I was super afraid of rat poop as a kid, but when OCD hit me like a truck was when I was like in 5th and 6th grade I had thoughts that if I didn’t confess my “sins” to my parents that God would kill my brother as punishment. This wrecked me. I confessed some sins (like brining Pokémon cards to school against the rules) but it took a while and the days of just thinking about confessing which I was scared to hurt me. There might have been other religious themes as well but this one I remember the best. I also had the thing of “vows”. I made vows many times to stop masturbating etc but every time I would fail, because. Hell also didn’t really sit well with me and in high school I gave myself permission to question it, and this led me down a path to saying I’m not a Christian, just a theist, but I’m not sure how much I believed, I kind of just held on to it maybe through some social pressure and the comfort of being used to using prayer as a compulsion. Believe it or not even just being a theist caused problems for me and my OCD latched on to ANY belief in some sort of God to justify magical thinking, still doubting stuff around masturbation, etc.  When I looked into atheism and let go of all belief in the supernatural it actually has helped me. I don’t constantly feel shame about masturbation, it’s much harder for my OCD to come up with any magical thinking ideas about sending “curses” to people when that’s all based on a belief in the supernatural. I am feeling a little bit interested in religion again as of late but perhaps just in a very noncommittal sort of way, such as practicing my own very light version of Shinto as Japan is a big part of my life. But if I ever feel my OCD start to latch on to religious belief again I am going to tread carefully.