Hello Mike: First of all, I want to thank you for always taking the time to respond to my questions. You describe my suggestion as " skirting the letter of the rule." I only see it as the proper way to assure that no player will ditch their hand prematurely. We have had instances when players have asked us what they should do when players muck their hands because an all-in player (not contesting the side pot) has them beat. It is an easy mistake to make, when you see a better hand than yours face-up on the table.
The only method I have ever used, is the only proper method that I still teach. I will always insist that the all-in player or players, will table their hand when the pot they are contesting is being decided. The all-in can never muck their hand without showing it. Cash games, of course, are different. If a player decides to muck a winning hand, that's their mistake and they have no one to blame but themselves. Tournament poker is different...so all players must show their hands to guarantee that the proper winner receives the pot they are entitled to. There must still be a proper order of showdown to protect all players. My suggested method is the only way to decide side-pot winners without confusion...that is: in the reverse order that they were created.
We have also addressed the subject of insisting that all players, in for all bets, show their hands at showdown. Not only when there is an all-in. This is the ONLY way to guarantee that there is no chip dumping, or collusion, or any type mistake that would give any pot to an undeserving winner. I'm sorry but, this would be the only way to "protect" the integrity of the game.
Let's at least address this important fundamental procedure. In my opinion, it makes no sense the way it is.