Gosh I wish I could help you. I tried googling but couldn't really come up with much. If it's helpful, washing soda is the same as sodium carbonate. If you can find sodium bicarbonate (baking soda) this can be turned into sodium carbonate by baking it for a while until it dries out and changes into a coarser texture.
Borax is sodium tetraborate, sodium borate, or salt of boric acid (NOT the same as boric acid). Sorry I can't be more helpful!