I have some small trees I collected from the area here which have root bals filled with clay...very thick clay. I cannot seem to free the roots from the clay without damaging them. Is there a deflocculant that is safe to use to wash and break up the clay without harming the plant?

Just give it time.
I find that clay will wash out, just a bit per repot. Don't try to get all out at once.
If you are bent on getting it out: put it in a tub of water and gently wash it. Normally clay gets very soft when very wet.

Thanks, I'll keep working at it,