Combine water, kosher salt, brown sugar, peppercorns, and bay leaves in a large pot. Bring to a boil, then cool to room temperature. Add optional garlic, lemon, and herbs. Submerge chicken in brine and refrigerate overnight.
Remove chicken from brine, rinse, and pat dry. Coat with avocado oil.
Mix smoked paprika, garlic powder, onion powder, thyme, oregano, cayenne, salt, and pepper. Rub over the entire chicken.
Heat smoker to 225-250°F. Use wood chips like hickory, apple, or cherry.
Place chicken in the smoker. Smoke for 3-4 hours until internal temperature reaches 165°F.
Remove chicken and let it rest for 10-15 minutes.