There is a little glass shrimp feeding dish which can help with a attempt at less mess feeding. There are pellets and little pads of food Glassgarten has some options too.
As for feeding, ShrimpBaby is a minute pellet, actually I really like it. And you can drop in a very tiny amount just periodically.
Not sure the numbers of shrimp you have but an easy fix is the Hikari Crab Cuisine. Makes sure they get additional minerals for shell building, other bottom feeders LOVE it and shrimp can pick up leftovers.
As for the dusty type foods for shrimp, you use just a tiny amount, like what fits one end of a flat toothpick, the larger end for many shrimp and the tiny end for few shrimp. The particles disperse in the tank, land on things and the shrimp graze around and eat them.
As a pellet could get lost in the cracks of the gravel, still bottom feeder fish are adapted with pointier mouths and extra whiskers for getting into the gravelly and sandy spots.
It wouldn't be something that you feed every day either, the shrimp are getting tiny particles from the foods dropped around the tank when the other fish eat.
And for mineral availability, I usually drop in a vertical slice of Cuddle bone. (Chop from soft side down longwise with a knife.) The plain kind for birds.
They float for a short time, sometimes longer. Put in soft part down / harder shell part to the top. When it finally does sink, I just tuck into the substrate a little, behind a DW / Stone / plant, like a surfboard in the sandy beach, and the shrimp can graze when they want to.
