Which treatment works the best and fastest for neonatal jaundice?

Depends: Often it requires no treatment whatsoever. Frequent breastfeeding and exposure to sunlight may suffice. If bilirubin levels are in the "high" zone and most importantly they are rising, your baby may need so called "light therapy" when he/she is put under uv light to remove excessive bilirubin in the system.

Phototherapy: If treatment is needed the best treatment is phototherapy, which is light therapy using special lamps or lighted blankets and exposing skin to them. Also one has to ensure proper nutrition and hydration. The fastest treatment is blood exchange transfusion but this is used only in very rare situations when jaundice is very severe and putting at risk baby's brain.