I bought a 2 oz bottle of Copolla Keratin Treatment from ebay twice. Each was different, one creamy white and the other a creamy brown. One was obviously not Copolla, probably some other brand, but it worked. One included 2 oz of the clarifying shampoo, but any clarifying would do. I bought the Copolla shampoo and it's ok. I also use Finesse which was $3 at Big lots. Just avoid sodium in products. The only thing I use now is a leave in, Sallys brand of Silk Drops. My hair likes cones.
You can buy larger bottles of Copolla from Frizzy 2 Silky if you want to be sure of brand.