In a coffee cup, mix the Tony Treachers spice with the applesauce.
Place the Boston butt on a bakeing sheet. I recommend you wear an apron and clear the surrounding counter space. Inject the pork every couple of inches with the applesauce. Insert the needle completely through the meat and while holding pressure on the plunger, slowly withdraw the needle.
Rub the exterior of the pork liberally with yellow mustard. Sprinkle with black pepper and insert thermometer probe.
Pre-heat the smoker to 225 degrees. Place pork in the center of the grate.
Cook until themometer reads 165 degrees. Remove pork from the grate. Baste with apple juice and wrap it in several layers of tinfoil or food grade plastic wrap (no it won't melt). Place the pork back on the smoker.
Cook until themometer reads 205 degrees. Remove pork from the grate. I recommend you leave the pork wrapped, swaddle it in old towels and place it in a cooler to rest for one or more hours.
Remove the wrapping and pull the pork. Reserve the juice. Enjoy!