I find that hydroslates do disolve completely . It's usually the micellar casein that leave clumps. In those cases you may need a blender. Even after I break open a capsule of digestive enzymes into the shake and leave it over night... a good micellar casein will still have chunks
I use all protein factory products. Casein, super amino 97, cfm whey ISO. My current favorite is the New Zealand whey protein. Thinnest shakes I've ever had especially with almond milk