Diaversal Process Chemistry?

I have some Diaversal paper and a Revere processing kit (Edwal) tho it is missing the powder one mixes with the #2 reversal solution. The instructions describe it as a white powder. Does anyone have a clue about what this might be? Sodium Sulfite? and maybe some alternative chemistry which will work with this paper? I was hoping to use it as a 'film' in a pinhole camera....
Thanks
Greg