Where I live, KOH is not readily available and is cost prohibitive to ship. A number of other materials are available, however. I have read similar questions and their answers here, but most are too general or too specific for me to understand.
I could mix NaOH and KCl, both of which are available, to yield NaCl and KOH. But I'm not sure how I would separate them, as I can't think of any readily available substance that could be used to precipitate out the Na.
Or, I could mix Ca(OH)2 and K2CO3, as that would produce CaCO3(s) and KOH(aq). However... I do not have K2CO3 available. I could make the K2CO3 myself, by baking NaHCO3 into Na2CO3 and mixing it with KCl to produce NaCl and K2CO3, but then I am back at having to precipitate out Na.
I could also make the K2CO3 by combining C and KNO3, but... again... I do not have KNO3 available. I could make KNO3 from KCl and NH4NO3, but that's not available here either.
I feel stuck. KCl, NaOH, and Ca(OH)2 are all available and relatively cheap. NaHCO3 and NaCl are also obviously available and cheap. What else am I missing here? What else is generally available and cheap that I could use to synthesize KOH?