Here's the mild cure I use:
For 2lb meat:
3 oz room temperature water
1 tsp phosphate (optional - I use
Con Yeager Curaphos, their product 1287)
1/8 tsp sodium erythorbate (also optional, also from Con Yeager)
1/2 tsp pink curing salt: 6.25% nitrite
1 Tbsp kosher salt
2Tbsp dextrose or sugar
Measure water, stir in each of the other ingredients in the order listed. Inject meat. Rub with spices if desired. Cure in fridge 3-5 days.
You can easily multiply the quantities. The last round I did weighed 4lb, so I just doubled up. I've used the same cure for turkey breast and pork loin. Turkey was OK, pork loin could have used more salt. I developed the recipe based on some formulas for much larger quantities I found on a university web site as I remember.
As to the parchment, it definitely lets smoke flavor through. I used Reynold's Parchment Paper from the grocery store and soaked it in water for a few minutes to make it easier to get a tight fit. It does absorb a little bit of water. Maybe the more common Quilon coated parchment works different - I haven't tried it.
This method started because my wife really likes Carl Buddig beef lunchmeat, the thin sliced stuff in the little packages. Now that's chopped, formed, etc, etc. So I thought maybe I could do something similar and even better with whole beef. I tried smoking with no covering, but the outside of my beef got too dry and hard to get thin, even slices by the time the center was done enough.
My reasoning was that fibrous sausage casing lets smoke through but holds in at least some moisture, and it's kind of the same thing sort of as parchment. So I tried it. The parchment winds up very wet at the end. The beef has only a thin (maybe 1/16") slightly tougher, darker outside layer and slices easily when cold.