GH Booster vs Calcium Chloride and Epsom Salts

I've been using Barr's GH Booster and nothing I do (stirring with a whisk, dissolving in boiling water, etc) seems to get me around the tank looking like a snow storm just hit after adding it. While it mostly dissipates after 12 hrs or so, I would still like to avoid it if possible.

I did some research and found that GH Booster consists of:
3 parts Potassium Sulfate
3 parts Calcium Sulfate
1 Magnesium Sulfate (Epsom Salts)

Apparently it's the Calcium Sulfate that is difficult to dissolve.

I was reading Rex's Planted tank guide and learned that Calcium Carbonate would add both GH and KH in equal amounts, but it too is difficult to dissolve.

Rex goes on to recommend using Calcium Chloride and Epsom Salts to boost GH and Baking Soda to boost KH. He notes that you need to add these separately or you will end up with Calcium Sulfate which is hard to dissolve.

The main difference between the GH booster and what Rex is recommending is Potassium Sulfate. While some descriptions of EI include dosing PS, I read that there is plenty of Potassium in the Potassium Nitrate.

My question is, does the Potassium dosing in EI assume that Potassium exists as part of the GH (whether added or existing in the water)? If I stick with the GH Booster formula, can I make it with Calcium Chloride instead of CS as long as I use it in a proportion that provides an equivalent amount of calcium? AquariumFertilizer.com sells both CC and CS.

Incidentally, my LFS said they reconstitute RO water for their tanks using a marine buffer product, but I'm looking for a solution that uses raw ingredients which come at a lower cost than commercial products.

Michael