As strange as it sounds these "Soap Nuts" really do grow on trees. The small brown nuts are the dried fruit of soapberry trees indigenous to Southeast Asia. The nut shell contains saponin which acts as a natural, low-sudsing detergent.
Place 3-5 nuts into the small linen bag (which is included in the box) and drop into your washer. The water temperature of your wash load determines the number of nuts needed. Directions suggest 2-4 for a warm water wash, and 4-5 for a cold water wash. The nuts can be used a number of times before discarding. That's good because the price is $10 for a regular box (20 loads), $19 for the family size (50 loads). The soap nuts are less harsh than detergent resulting in softer clothes without the use of a fabric softner. Not having to purchase fabric softener helps reduce the overall cost.
If you're looking to replace your laboratory detergents and softeners with something all-natural, 100% bio-degradable, and safe for sensitive skin, this just might be the ticket! I haven't tried them yet, but I plan to. I'll let you know how they work.