I love this little “hack”! I do this often, not because I can’t palm cards, but because it is so much fun to do it right under their noses.
Have one of the well known gag cards with 52 printed on the (with a matching back for your deck) in the left trousers pocket. Fred Kaps wallet is set up for loading in the inner right jacket pocket.
Have two cards chosen, signed and returned to the deck.
Control them both to the top.
Get a break underneath them.
State the cards will travel to your left pocket. Reach in and withdraw gag card with back out. Turn and show that the first spectator’s card is indeed on this card. Place the gag card face up on top of deck in right hand. Show it to the other spectator to confirm his card is also there.
After that lousy “gag”, which qualifies you as a first-class entertainer, apologize, pick up all three cards above the break as one and apparently put it into the right inner pocket (don’t do any flourishes with the triplet here). In reality, load all three cards right into the Kaps wallet. Call this bold. Put in some time misdirection, remove the wallet and produce the cards. Done!
P.S.: Many times magicians don’t get the gag and therefore the loading of the cards. If so, I pretend to bottom palm the chosen cards from the deck. I love when they credit me with an “incredible” bottom palm (although I can do a decent one).
Have fun!