Even if you'd sell your Bitcoin on the same KYC exchange so you can show you have nothing left, the moment you use a non-KYC exchange to buy Bitcoin again it will be linked to your bank account. If I'd send/receive a large amount to/from an established exchange, my bank asks less questions than if that same amount comes from different unknown foreign bank accounts.
If you withdraw cash from your bank account and buy Bitcoin P2P, you'll end up with a problem if you later sell and get a large amount of cash. That stuff becomes more and more restricted to spend in large amounts.