I use different sizes of sifters, depeding on the size of the bedding/gutload (why is there saw dust in your mealies?) you will need one that allows the mealies to stay inteh sifter and the bedding to fall through.
Im thinking you are talking about some kind of bran or wheat germ. A spaghetti sifter usually works well for getting the bran out. If its a finer better you can usually use a wire basket type sifter.
I feed a part of a carrot and come back in a half hour. Seems like thy all collect at the food. It's super easy to pick up the food, shake into a container w/o getting any bedding.
Then, where the carrot was, scoop the mealies and transfer to the other hand to reduce the bedding.
Works great!
I personally use a spaghetti strainer...specifically for my mealies...LOL. They're cheap, especially the plastic ones...I think I picked mine up for $1-2.