I've started using a card protector.

oh wow is that even allowed lol?

That's one of those things you always think will happen to someone else until it happens to you. I've seen dealers accidentally kill a live hand when the cards were left too close to the muck, especially if there wasn't a card protector on them. Your homemade card protector sounds like a practical solution, and honestly it's kind of cool to use something you made yourself instead of buying a fancy one. Ever since I saw a similar mistake at my local casino, I've made it a habit to keep a chip or protector on my cards whenever I'm waiting to act.