Ok, I’m about to take the plunge into using wool dryer balls. They should save time (drying loads faster) and money (no more dryer sheets needed and less time drying means less electricity used!)
How dryer balls shorten drying time:
When you add dryer balls into your clothes dryer the balls will get in-between the clothing. The balls will separate and pull them apart with their weight. This in turn is allows more hot air in and around your laundry helping the dryer to heat your laundry more quickly and suck the evaporated water out of the dryer more efficiently.
If you want, you can add some essential oil in the wool dryer balls before use, then you will get more fragrant clothes.