I've been working on an article for RealDeepDish.com on deep dish "hardware",
and naturally it will have a section on "seasoning" deep dish pans.
In other locations in the pizzamaking.com forum, we've had discussions on the best way to achieve a darkened coating on our pans.
Part of the problem is that there are many styles of pans available, including non-plated bare steel pans, which you can sometimes find at a restaurant supply store, often pre-treated with a mystery coating that needs to be pre-baked before you use it. If you have a pan that hasn't been pre-treated, you might want to try seasoning it yourself.
Most recommend adding a light coating of oil (with a high smoke point) to the pan, which would then be baked empty before first use. Repeat the oiling and baking until the pan darkens, or just keep using the pan to make pizzas.
I think it was Loo Waters who suggested using tomato sauce or something with sugar in it to more quickly blacken the outside of your pans. The concept being that sugar and carbohydrates would more effectively burn and turn into carbon (aka blackened). Once you've blackened your pan this way, you could use light coatings of oil to keep the pans seasoned.
I suppose you could just candy-coat your pan with oil and sugar, and then just caramelize the heck out of it on your bbq grill until it blackens into a layer of char. Let it cool, wipe it out, oil it, and rebake.
However you season your pans, I recommend seasoning your pans outside in your bbq grill unless you have really excellent oven ventilation, because burning things makes eye-burning smoke that can smoke up your home for months.
Your other option (besides buying someone's pre-seasoned pans on ebay)
is to buy the various pre-blackened pans with proprietary names like PSTK (Pre-Seasoned Tuff Kote), BlackBuster or Bakalon.
I am curious, however, about the sanitation methods for blackened pans.
Because seasoned pans are supposed to be cleaned with hot water and never soap, what would be the proper cleaning, drying, and storing method for blackened deep dish pans?
If one of us were to run a deep dish restaurant in Chicago, for example, how do we keep up with the sanitation codes if we choose to go with our seasoned pans instead of the industry-coated ones I listed above?