Do I need to add MORE Darvan 7? Making slip from slip casting trimmings

I've collected a lot of trimmings (and failed pots) from my slip casting process. I also ran out of slip to cast pots. Here I go through the process of turning bone dry clay from my slip casting process back into slip for new pots. I wondered if I needed to add back more Darvan 7 which is the deflocculant I use. The instructions say no. I slowly add more and more water letting it sit in between so it is absorbed by the clay. Eventually I get back to a slip casting consistency and cast a new pot!