We used them exclusively for a few months.
I bought a kg of soapnuts last year, with two drawstring cotton baggies to put'em in (five would have been easier), and I put away our washing powder and told my partner that we're using these, exclusively, from now on, cos I'm green.
So we did. Soapnuts work, kind of:
Soapnuts work a treat on "normal" dirt. (But then, just water sloshing clothes around in the washing machine might be as effective).
Soapnuts do not keep white clothes white (no bleaching agents), so about three weeks into the soapnuts I started to add 1 teaspoon of sodium bicarbonate to each white load. Which made the white washings hard, when they dried, but they were whiter again.
Soapnuts can't get out the stinky bacteria. So you wash your favorite T-shirt, the one you've been wearing whenever it's been clean for the last 10 years or so, and the armpits smell (smell!) after about five minutes. Right, thought I, time to throw that T-shirt out, it's obviously way past its use-by date. My partner didn't think that way: these are perfectly good clothes, and they don't smell five minutes into the day when you use commercial detergents, so tell me again, why are soapnuts a "green" way to do things?
So we're using commercial detergents again - ones marked "nature-friendly", as I refuse to buy any other kind.
And if one or the other of you sits on a mountain of brand new T-shirts: I've got quite a few to few, right now, cos I threw out quite a lot of my lovely old ones, and I haven't had the time to stock up on new ones yet. (I buy T-shirts at every botanical garden I visit that sells'em, which can get interesting: Gothenburg, June 2005, I spend one day at the botanical garden, buy a T-shirt, drive off into the sunset come evening, visit the botanical garden again two (or was it three) days later wearing that T-shirt, and everybody asks me "where is this plant, where is that plant". Heh.)
Related entry: Soapnuts