Curing bad habits

[dachord]

I've been playing in a regular home game for the past 2 years. Most of the players rarely play at B&Ms, so they are by and large ignorant of proper play and table etiquitte. Otherwise, they're good guys and always bring a lot of money to the table. With that in mind, two of the other regulars and I have slowly but diplomatically "corrected" most of their bad playing habits. Here are some examples of the bad habits that have been corrected:
1. Talking on cell phones while playing.
2. Continuous Betting out of turn.
3. Making comments or analysis about the hand in play.
5. Walking away from the table for something like a bathroom break and then getting upset when they are dealt out.

Like I mentioned earlier, these are decent guys (for the most part) but they're just a little ignorant in some respects of poker etiquette.

Here's my question: So far we have been unable to break their habit of openly discussing the cards that they folded while the current hand is still in play. They've even gone as far as digging into the muck pile and pulling out their cards. Example: UTG raises, everyone folds except the BB. Heads up play. The flop comes out 233, one of these guys grabs the muck pile, pulls out his folded cards and exposes them showing that he folded a 23. I've tried to explain to them why this is wrong. They nod their heads as if they understand what I'm trying to convey to them, but it only lasts 3 or 4 hands before they do it again. I'm open to suggestions as to the best diplomatic approach to correct this habit. It would be very easy to make crass comments when they do this, but this approach would have a -EV, these guys have money and don't mind donating (if you know what I mean), so crassness or blunt threats are out of the question. Comments?