While digging up the sourdough waffles recipe, I found the recipe for pretzels on FCS - made with baking soda, tsk tsk tsk Jacob. I would expect such things for the likes of Alton Brown but you are the guy I go to to hear about the magic old world secrets all of today's busy bodies never want to learn about.
I am a big believer in pretzel buns as the answer to stand up to the ultimate juicy hamburger loaded in toppings, and have been making them quite a bit over the past few years. I have yet to try slow fermented pretzels, let alone sourdough ones, I but they will be fantastic.
Do you guys make stuff with lye like bagels and pretzels? I have found that the soft chewy dark brown surface is only posible with a 3-5% lye solution. I have never had a problem with the lye but I have learned that you do have to really be careful with your cookware, it will eat through aluminum, steel and even sil-pats, I only bake them on stainless racks over stainless hotel pans now that I learned my lesson.