There's a tool invented by a 13-year-old Kiwi girl called the Kindling Cracker. Same principle, but with an integral ring to keep hands/striking tools above the splitter:
https://www.core77.com/posts/55548/...vice-That-Safely-Turns-Firewood-Into-Kindling
I saw one of these the other day. I reckon the bane of the wood splitters life is knots, and knotty bits need beating down sometimes right to the blade. Could be a problem.