I have a simple marinade that is highly sought after (for me to grill) by family. I will share it but it's not measured ingredients.
1. Melt about half to 3/4 stick of butter in a sauce pan. Use medium heat.
2. Add most of an 8 ounce bottle of yellow mustard.
3. Stir that until blended
4. Add about half a can of beer, drink the remainder.
5. Add a bunch of salt and black pepper.
6. Throw in a few dashes of Lea & Perins Worcestershire Sauce. (Don't use cheap imitation stuff)
7. Add some garlic and onion powder.
8. Add a dash of Franks Red Hot Sauce (again, don't use cheap stuff).
9. Add Apple Cider Vinegar (about an inch and a half of the bottle. Maybe 2 inches).
10. Simmer for about 10 minutes. You know it's right if you take a whiff while it is simmering and it takes your breath away.
Then use as a basting marinade on the chicken (legs and thighs are best) while it cooks over charcoal or wood. Gas grill does not work here. You need to keep basting and turning every 6-8 minutes. Cook well done but not burnt. A nice crispy brown is best.