Downy will cause white spots on dark clothes if it's poured directly onto clothes. If there is even a small amount on the ball after pouring it in, it will cause spots. When you put the Downy ball in, make sure the tub is full of water first.

I've been using the OxyClean Laundry balls and love them!!! Two balls will wash 95 loads. Just put them in with your clothes. My whites are much whiter. BB&B sells them.