I’ve worked for both Domino’s and Papa John’s as a driver and pizza maker on and off since I was first in college nearly twenty years ago. Always used it as a go to job when I was between employments or needed to earn a little extra cash.
The stuff on the bottom of your pizza is added during the dough forming process and is there to help keep the dough from sticking to the work surface and pizza screen, and to add a little extra texture to the crust. At Papa John’s it’s called “Dustinator” and is a mixture of corn meal, corn flour, all purpose white flour, salt, sugar, and a bunch of different chemical preservatives. At Domino’s it’s just straight corn meal. All of the pizza dough products for both chains are made at central production plants and shipped to the individual stores on refrigerated trucks. It is only “proofed” (given the second rise) at the stores. Honestly, I think you can find much better pizza doughs to imitate than either of them. Your favorite straight French Bread dough recipe makes an excellent pizza crust, and most non-chain pizzerias use a version of that for their pizzas.
I would be more concerned with the quality of their toppings, especially the cheese, at PJ’s and Domino’s. Both arrive frozen and diced into tiny cubes, then are allowed to thaw at the stores. You may have noticed that ads for both chains contain the words, “Made with 100% real cheese,” not “Made of 100% real cheese.” That’s because it’s not 100% cheese.
By USDA definition, real cheese may only contain the following ingredients: milk, cream, whey, a coagulating agent (Rennet or other enzymes), bacteria, mold, salt or other flavorings. If you look at the boxes, the “cheese” at the large chains contains a list of over a dozen different ingredients, mostly extenders and chemical preservatives. For example, listed as the third ingredient in Papa John’s “100% Real Mozzarella Cheese” is powdered cellulose, i.e., SAWDUST! YUM, YUM!