creating a starter from fresh bakery sourdough pizza dough?

Toast

Hello all,

I had a starter that I used casually for about a year. Then things changed, and I neglected it, and it's no longer with us. I'm trying to get back into making sourdough, and instead of trying to make one from scratch again, I thought I'd ask local bakeries if they'd sell me some. No dice there, but a local coop bakery suggested I buy some of their fresh sour pizza dough to use to start my own starter. 

Does anyone have experience creating a starter from prepared dough? Any advice? 

Thanks!

uses old dough for all of the SFSD bread - Boudin..  So any sourdough bread dough is already nothing but old dough.  Your starter is done. Just let it ferment and then take a piece and feed it flour and water and let it ferment - that is all there is to it.

is nothing more than a just fed SD starter, or an hour later, what Chad would call a young levain  with a bit if salt in it.  Once the dough rises twice and is ready for the oven 6-8 hours later, it is nothing mie than a ripe starter or levain with a bit of salt in it.