I guess we could go through a challenge. You set up a Stripe page or some such thing and someone else can set up a BTC wallet. I will spend a dollar with my CC on your Stripe site and I will spend a dollar equivalent to that BTC wallet.

Then I will make two other secret transactions with the CC and the BTC wallet. You can each then try to identify the targets and the sums spent in the secret transactions.

Whoever identifies gets some sum of money from the other. I'm happy to escrow for you.