I wouldn't be so certain, yet. Just because no one uses CMC gum as a substrate is not necessarily because it won't work, but because hardly anyone does original experimentation. You know of it because you're a potter, but I'd bet that most alt processors don't know what it is (I certainly didn't before PE mentioned it to me privately).
Originally Posted by Erik L
The only way to be sure is to try it yourself and evaluate the results.
I'd encourage further exploration.