Powdered Bentonite is extremely hard to mix with water. It may be that you are using entirely too much powder whem mixing. A tablepoon of liquid Bentonite is NOT equal to a tablespoon of dry bentonite. You would use a considerably smaller volume of it. How much I don't know but I would start with 1/2 teaspoon and go from there. Also to help mixing you might try mixing it the day before so that it has time to dissolve. Also chase it down with another glass of pure water.
Those of us in places that have easy access to all the "proper" stuff sometimes forget or don't realize what it is to live in a place that one may have to improvise ingredients. Do try to find a source of grade B maple syrup on the internet that will ship to Namibia. It is so much better tasting - just like Grandma's lemonade with a hot twist. Best of luck.