wet, grey is a great lipid based clay, but its very "crumbly" if that makes sense.
If you have access to a strainer you will be golden. Take loose huge clumps of the dirt and let it settle in a basin of water. "wash" the dirt away and grab handfuls of the gray/red lipid feeling dirt and process that over the filters.
one you have a good amount of that red/grey sludge an can handle it to the consistency of play doh, a light arm fire will be enough to harden it.