These materials are comparatively expensive and probably feasible only to amend small plots or small amounts of potting soils. Like household detergents, liquid products break the surface tension of water around the soil particle and allow deeper water penetration. They in no way increase the pore space of a soil. They are not substitutes for amendments. In other words, adding gypsum to a soil that does not need calcium is a waste of money.
Gypsum increases salt levels.
The use of sulfur in a clay soil high in calcium also has been acclaimed by some as a method of breaking up a tight soil. While sulfur added in small amounts over a long period of time eventually can improve the soil condition and reduce soil alkalinity, this practice generally is not advised because the sulfur reacting with the calcium simply forms gypsum. These soils normally are found where there is a high water table and poor drainage. Such soils are hard and cloddy when dry and take water very slowly. Few plants can survive in them.