First off, yes, I know it's probably not a 'cured' product without salt, but I'm a custom shop, and it's an experiment for a customer. I'm dispensing with the terminology and calling it cured for my purposes.
So, I have a fellow who brings me whole boneless pork loins regularly who likes a low-salt cure. Normally I do a brine pump and a curing salt rub on my items. His, I just brine pump and leave the outside alone. It's low, but he asked if I can do a no salt cure. Being an experimenter at heart, I said sure.
My plan is to dissolve some of the pure sodium nitrite I have for curing sausage (6.22%) in water with some brown sugar and 1/4 to 1/3 teaspoon vanilla, then pump the loin and leave it alone for a few days. It'll be smoked with a regular smokehouse load of curing (cold smoked for color for 4-7 hours, depending how the color looks) then cooked in smoke to 140F.
It won't be 100% salt free, obviously, but pretty close. Has anyone tried this? I know the color will be fine, but flavor is going to be my worry.