Theoretically those ball valves sounded good, but...
Just to be clear for other readers, this is a ball valve. Bob is talking about a "ball check valve".
For same amazing reason, several manufacturers were making snorkels with a upside down "U" at the top and a captured ping pong ball, functioning as a ball check valve to keep water out. Had any of them actually tested a prototype before investing in tooling and inventory it would have saved pool owners a lot of money in the 1950-60s.