Tong feeding can be useful to prevent substrate ingestion, which happens pretty easily when feeding earthworms or insects like mealworms who burrow. To be honest, I completely mis-interpreted your post and thought you said you were "tongue-feeding." lmao...the mental image of a mealworm on the tip of someone's tongue being fed to a frog...

The shrimp things I assume are pupae. Frankly, mealworms are one of the most effortless feeder insects to breed. You don't necessarily need to separate pupae from larvae (worms) or from adult beetles. They will all thrive in a single container, couple inches of bran, some salad items from time to time, and kept at room temp. There are certainly ways to increase production, but this is the bare minimum and works just fine. I've allowed mealworm cultures to go for over a year without any feeding or watering and STILL had babies popping out.