Is it inert? Yes. These are like koalinite, which is the stuff that coats paper. These are just ordinary clays and montmorillonite--well, there are traces of that. It's inert, just like anything you'll find in your soil in your garden. The things that may not be inert are the soluble particles in the water, which is still in the pores of that mixture--the organic compounds, the salts, and so on.
