Steve_ , I think no to the bentonite, it is too dispersive IMHO. Before I did any treatment I think I would solve the vegetation issue. I would try to establish a grass that doesn't bunch but spreads (like Bermuda or buffalo grass). An annual can help also by providing immediate soil stabilization where the spreading grass can take over the following year. For annuals I like rye, wheat, or oats.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers