Reviving this thread because I've learned something since my last post here. Specifically, you can place a small, flat magnet at the BACK of the shell, not the front as most magnetic shells do

For me, this gives WAY more control over the pea's "engagement" with the shell and makes my current finale downright easy

Construction-wise, just use the smallest, flattest magnet you can find, glue it to the shell's back and cover the entire shell's interior with wood epoxy putty. Sand with a fine grit afterwards and it'll look perfect

This version works perfectly on any surface, no need for the close-up stage I described earlier

Last point: I place the loaded shell in a spectator's hand to "take it out of play." I tell them that if the pea escapes the multi-covered shell into the empty shell, "that'd be a good trick right? Like the best possible trick, right?

The goal is to prompt one of the audience members to point out that a BETTER trick would be for the pea to appear in the spec's hand. I get about a 75% success rate getting someone to say it. Makes for a very funny ending. Once the tabled shell turns up empty, I openly glare at whoever suggested the other ending before showing that he was right ... and the pea IS in the spec's hand

It's a very satisfying conclusion

What SIZE bottle caps are mentioned in some of these posts ?
2 Liter size ?
3 Liter size ?

IF . . . a person is betting, then there should be no other "magic" (Cups and Balls, ring off rope, cut & restored rope, etc.) or the word "magician" ever displayed or uttered during a gambling-betting game ?