What are you feeding?

If it's large enough for tong feeding then use tongs. This will almost completely eliminate any ingestion of the eco earth. I really can't imagine what you'd be feeding other than nightcrawlers that elicit a food response that causes them to scoop up eco earth.

I've never seen them eat it with crickets. Never seen them eat it with anything they can nab with thier tongue. Only when I feed worms do they eat the eco earth. I put the worms on a 10 inch tupperware lid so they never have a chance to eat the substrate.

Feed with tongs, or feed non slimy creatures that thier tongue sticks to, or feed on a 'plate' or dish as Bruce suggested.