That was basically Tin Chloride based like mentioned in the video, also used Urea instead of Thiourea, but no idea how they got it to work..Might have used a now banned chemical on top of it. The process in the Video, is actually based upon patents from the older product in the 80's, what they did was swap out the chemicals for OTC sources of them instead.
But most people in most countries can get the base chemicals from Amazon or Ebay. The question becomes, WHY?? EVEN me, I now buy boards in from China, they are way cheaper to order than make! I am looking into gold plating home made boards however.
I have a board that in an idea world I would gold plate from gold scrap.