Saliva. Works for me.

I like this performance from Benjamin Barnes -
https://www.youtube.com/watch?v=bkrawP_Fqjw

He fools Penn and Teller using a couple of very simple, old techniques.

I love how FAIR he makes everything. Using a new deck sealed in its cellophane wrapping. And inserting the Joker to select a card.

To me the f—— is weak.

I was able to reverse engineer it pretty easily. But I was already familiar with the technique in question.
It fooled Penn & Teller though. Also there are a LOT of erroneous explanations in the comments under the YouTube video. So I think it is only obvious if you already know the answer.
Likewise the way he was able to find the card.

I rather like this too -
https://www.youtube.com/watch?v=zo6E12AwpoI

The female spectator selects a card and shows it to the audience. She replaces the card in the deck, and it instantly disappears.

Devious/Seer by Mark Calabrese

Bring the card to the top.

Cut off the bottom half of the deck and table it. Ask the spectator to pick up the bottom half and while he is doing that, tilt the top half of the deck over towards the edge of the table and thumb the top card off into your lap.

Voila! The deed is done. Now you can use (your favorite method) to reveal the now-vanished card. My personal preference is a Mercury Card Fold.

Check out The Easiest Card Control shared on this site and read his thoughts on it's use.
https://www.thejerx.com/

I'm reminded of a gimmick from Ludor Fiedler on page 82 of Tarbell 7. The card naturally disappears from the deck. I think Henry Evans had an elaborate version of the gimmick, but I doubt that it's necessary. Daryl Magic had the gimmick, so you didn't have to make one.

Joshua Jay
REVERSE LOGIC (starts at 7.45 minutes)
https://www.youtube.com/watch?v=Kl_6yEZF4dI

JJ riffles through the deck. Spectator says stop. JJ tells them to remember the card they see. He immediately hands them the deck and asks them to take out their card - it is gone

The card is never in the pack from the beginning..

Theodore Annemann's Peek Force Card (Jinx, 1935) is another great gimmick to accomplish what the OP asked for. Still used today from what I can see.