I've had bad experience with CEX's that held my funds and requested too many documents about the source of funds...
The thing is, I don't want to use a service, that might lead to a blacklisted wallet in future.
I've seen ppl mention Bisq here a lot. But I can imagine that there are a lot of blacklisted wallets trying to wash their coins, so not sure if that's a good idea...
Maybe I'm wrong, because I don't know Bisq and never been using it...
If your source of funds is genuine I don't see why you should be worried and not want to provide the right documents. I doubt your funds is as big as those institutions who have large sum in exchange and can move them anytime because of transparency.
I don't think you have too many options than to either what is suggested above, use one of the mixers suggested above or use privacy coins.