Cut chicken livers into 36 1-inch pieces.
Discard membranes; set livers aside.
Combine soy sauce and garlic powder; set aside.
Place 1 piece liver on 1 piece bacon.
Top with water chestnut.
Roll up and fasten with wooden toothpick.
Repeat with remaining liver pieces.
Dip each into soy sauce mixture.
Place 18 rumaki on microproof baking sheet and cover with paper towel.
Cook on HI, 7 to 8 minutes.
Repeat for remaining rumaki.