With regard to the EZ-Rodinal, It would probable be best to dissolve the sulfite and hydroxide at about the same time. IIRC, the sulfite is endothermic. Certainly, the KOH is potentially dangerous. Worse yet is adding water to the dry hydroxide, either K or Na.
I have made KOH upon occasion. I had the potassium carbonate, and can get calcium hydroxide at a garden shop (they call it "slaked lime" or "hydrated lime") . Mix one molecular weight of each in water and you get a precipitate of calcium carbonate and 2 molecular weights of KOH dissolved in the amount of water you used. You'll be hard pressed to recover all the solution by filtering, but the amount that can be decanted after the limestone has settled will be the same strength as what is trapped in the limestone. Just get the precipitate out of the container before it dries if you want to get it out without some acid.
Go ahead. It's OK to laugh.