I dry-brine belly bacon using 2% by weight of salt, 2% by weight of brown sugar + a couple of glugs of maple syrup, 0.25% by weight of Prague Powder #1 (actually for years I didn't even bother with Prague powder but I am getting more cautious in my old age). Pop the belly in a large ziploc (half a Costco belly - about 5 lbs - goes in a 2 gallon bag) and rub the mixture all over the meat. Squeeze all the air out and seal, then in the fridge and turn every day for a good week. Then rinse off the rub, pat dry and in the smoker low+slow. I usually pull at 153. Comes out pretty good.
For butts I have been doing a wet brine, so not the same as for belly. Thirdeye probably has views on this that are worth listening to.