About that Disney turkey leg brine being dangerous in terms of nitrite amount.
FWIW, here's how an immersion brine is checked for safety (it's important to remember that only a portion of the cure is absorbed into the meat.)
Weight of the Nitrite x Percentage of Brine Pick-Up x 1,000,000 ÷ Total Weight of the Brine = PPM Nitrite
4 teaspoons Morton's Kosher Salt (19 grams)
1 teaspoon Prague Powder #1 (5 grams)
3 tablespoons Dark Brown Sugar (45 grams)
1 cup Warm Water (237 grams)
Weight of the Nitrite... 5 grams of Cure #1 x 6.25%=.3125 gram Nitrite
Total Weight of the Brine=306 grams
At 10% Pick-Up....
.3125 x 10% x 1,000,000=31250
31250÷306=102 PPM Nitrite
At 15% Pick-Up....
.3125 x 15% x 1,000,000=46875
46875÷306=153 PPM Nitrite
It may not even hit 10% pick-up.
Well within the 200PPM government limit used by many folks as a measure of safety.
HTH