What kind of trout? How big?
The answer is still frozen minnows. Just depends on how big of minnows.
Dead work fine too but those bastages don’t die even when you put them in a plastic bag in the bed of your truck and drive two hours in 0 degrees. That’s when I started freezing them the night before. I got all the heads chopped off by the time the warden walked up to the tent. Just in the nick of time.
If you gotta downsize to waxies you may as well break in to the hatchery and fish the stockers out the tanks.