I purchased food grade Bentonite as well as havingused the liquid before....the liquid is MUCH more convenient but I'm not about to throuw out the powdered.
Kind of primative but....
Put some clay in a glass jar with a lid, maybe 1/5 to 1/4 full. Put water up to about an inch from the top of the jar. Put the lid on tight and shake. Shake some more, shake until you have had it with the shaking. Now you should be able to pour off some of the thickened liquid into another container for use and just add more water to the original jar and shake whenever you think of it.