Spouse/partner who only likes the pretzels.

You can make a tray with holes slightly bigger than a pretzel piece and shake everything through the holes. What stays is everything bigger than the pretzel but all the pretzels and smaller go to a lower tray.

Then in the lower tray you have holes slightly smaller then the pretzel and you shake everything through.

Then everything smaller than the pretzel is on the bottom tray, combine that with the top tray and you’ve got yourself a prezelless snack mix.

Buy the individual compenents- the little corn chip rings, Cheetos crunchy and chex mix and mix them together.

If you’re feeling really ambitious then also get pretzels and mix in so that you can use the other commenter’s Arduino Lego contraption to remove them.

pour the entire mix over a coat rack or similar assembly of hooks. this will remove any looped snacks

Your clean dry fingers. Have 2 bowls. Cup your open dominant hand like Shaq palming a basketball, with your palm up. Pour slowly into it. Wriggle your fingers and palm as necessary to catch the pretzels and let the rest pass. Pause to toss the pretzels into the reject bowl. If necessary, pick out the few that escaped into the keep bowl. Then pour a little more. Continue until the bag is empty, then pour the keeps back into the bag. You may now lick the salt off your hand. I suppose you could try using crushed pretzel bits as fried-chicken breadcrumbs, but cut back on salt.