I would want something with a smooth face for ease of cleaning. The nooks and crannies on a handmade tile in my mind would be much tougher to keep clean.

Agree with millworkman - it would not be for me. But if you have your heart set on it - make sure you squeegee, wipe down and have a humidity solution to ensure that the shower is fully dried after each use.

If the above is unlikely to happen, go with something easier to maintain / less nook and cranny-y

Thank you. I decided against it. Backsplash is okay but showers is too much of a commitment for me. Many thanks!!