Propylene glycol has some use among cattlemen, but I can't remember what it is. It should not be on any kind of controlled substance list, as it is used in medicines as an inert, or nearly inert, solvent. You can do without the TEA by using a second alkali component as is done in the Pyrocat developers. In my original article in Photo Techniques, I had a recipe for PC-Glycol. All the Pyrocat series developers can be put up in glycol.
You could make a solution in glycol of the developing agents found in Xtol or Mytol and a separate solution in water of the other ingredients. The developing agents are in most need of the protection of the organic solvent. Sulfite, carbonate, metaborate, bromide, etc last quite a while in water solution and in any case, may be made in quantities small enough to be used before they go bad but large enough to be convenient.
My first experiments used automobile antifreeze as solvent. It contains other ingredients beside the glycol, but they seemed to have little or no effect on development.