Do not use the earlier link for Potassium Sulfide...
What started as Potassium Sulfide ended pointing to Potassium Sulfate (in the search that was ran), which is not likely to work.
Try this one (I checked it personally)...
http://www.rainbowsupply.com/search_...rch=fromSearch
The cost does not look too bad, but there is a $10 handling fee on top of shipping that ends up costing more than the product (almost sounds like some of those "rare" swords on ebay
).
My apologies for the mistake.
