I actually found a cuban tree frog in my toilet once. Fortunately I was the one that found it and no one was home. I think this was when I was still convincing my mom to let me get my first snake.
I hadnt done any 'business' yet when I saw it and caught it, but being as it was a fairly large frog and it was very much wet, I had a struggle keeping grips on it and had to catch it a few more times before I found my way downstairs and outside the back door.
That was a pretty insane frog, but I enjoyed the fight it put up. Id be surprised if it had many health issues considering its liveliness.
If i found the cornsnake, I'd probably keep it as I've always wanted to catch my own WC corn, but my area of S. Florida just doesnt seem to harbor em.