Combine all brine ingredients and stir to dissolve salt and sugar. Pour over duck meat. Cover and refrigerate for 3 hours or overnight. (Can skip this step if needed.)
Remove from brine and soak duck breasts in cold water for 2-3 hours. (Can skip this step if needed.)
Pre-heat gas (or prep charcoal grill) to medium high heat.
Slice jalapenos in half and scrape out white veins and seeds. Rinse.
Slice duck breasts into strips.
Season duck meat slices with garlic and pepper. (If NOT brining, also add salt here).
Fill each half of jalepeno with cream cheese and lay duck breast strip on top.
Cut bacon strips in half and wrap around jalapenos, duck and cream cheese, tucking ends underneath (or can use toothpicks to hold together).
Brush or spoon hoisin sauce liberally on both sides.
Grill duck meat side down on gas grill set to medium high for 8 minutes. Then, flip and cook 5 more minutes. Baste with remaining hoisin sauce while grilling.