How can I change the seed of a substance with BP

I’m trying to change the random seed of a substance in a BP so that I don’t have to make a dozen variations by hand to keep the environment from looking to repetitive. I’m sure this is possible cause of a thread on Allegorithmic’s forums. For whatever reason I’m getting no feedback in the viewport. I also checked out the Gynoid demo at least 3 times and I don’t even see a single reference to a substance at all. Any ideas?

I’ve tried other combos of nodes but this is my latest.

Did you manage to do this yet ?
I’m having the same issue too