In a large bowl, mix together the pineapple juice, soy sauce, ginger, garlic powder, and white pepper. Reserve a small amount of the marinade separately for dipping later.

Place chicken in marinade, and add enough water to cover. Cover, and refrigerate for 24 hours.

Heat an outdoor grill for medium-high heat.

Brush grate lightly with oil. Grill chicken 5 to 7 minutes per side, depending on thickness. Chicken is done when inside is no longer pink and juices run clear.