Combine the first 7 ingredients in a bowl large enough to hold the chicken. Trim excess loose skin and fat from the chicken. Add the chicken to the bowl and turn to coat. Cover, refrigerate and marinate the chicken for 4 hours, or overnight, turning occasionally.
Remove chicken from marinade and set on a plate. Discard marinade. Use paper towel to remove any excess (overly wet) marinade on the chicken.
Preheat your barbecue to medium-high. Lightly oil the grill. Season the chicken with salt.
Grill the chicken 2 to 3 minutes per side, or until the exterior is nicely coloured. Move the chicken to one side of the barbeque. Turn the heat off on that side of the barbecue; leave the other side at medium-high. Cover and cook, turning the thighs from time to time, for about 30 minutes, or until cooked through.
When the chicken is almost done, place the butter, 1 Tbsp. lemon juice, hot pepper sauce and cilantro, mint or parsley, in a very small pot. Set over medium heat and cook just until the butter is melted. Removed from the heat.
When done, arrange the chicken on a serving platter. Top each thigh with a little of the butter mixture, garnish with lemon slices and serve.
Options: Instead of thighs, marinate and cook 8 to 12 chicken drumsticks. For very spicy chicken, double the amount of chili flakes used. For a sweeter citrus taste, replace the lemon zest and juice, with orange zest and juice.