Hi Sarah 
I have heard about soap nuts before, but haven't got round to trying them, after reading your post I've ordered a trial size pack. It actually made me think about the days when I was a little eco worrier (yes I did spell it right lol!) I worried about all the toxic chemicals in everything (still do), I did use ecover and other green products, but in this busy life we all lead, I confess I lapsed and used the named brand cleaners that supposedly make your house wonderfully clean, with little effort! But that takes the soul out of cleaning and I'm re-discovering the joys of cleaning using the methods our grand mothers and great grand mothers would have used. Chiefly elbow grease, hot water, herbs, a pinny and a mission to clean. Although I add essential oils and a couple of other ingredients like bicarbonate of soda. So if soap nuts work, then I'll be able to substitute them for the washing powder, I wonder if they'll work on for cleaning the floor as well? Simon isn't convinced they'll work, but then I showed him the joys of soapwort and he was impressed. So I'll try them when they arrive and let everyone know what results I get.
I haven't tried vinegar in the final rinse of the washer yet, although I have heard about it, it would be a wonderful use of the lavender vinegar I made, and also for the orange and lemon peel vinegar! So when the soapnuts arrive, I'll do a wash with eco friendly washing assistants. This summer I'll be making some rose petal vinegar as well (never tried that before) and I think that will be good for the washing to!
I do agree with Jim Macdonald though, having long hair myself, it is harder to get the soap wort on your hair, I came up with a solution, I put the decoction in a spray bottle whilst warm and spray it on my hair and massage it in. As an aside, whilst I was looking for soapnuts for the washer, I found a site were they sell it in a powdered form to make shampoo with, first time I've seen it being used in a cosmetic way?
Another recipe that I use for shampoo that I omitted to post is for a dry shampoo it's easy to make, herbal and works! It's just 25g Orris Root Powder (Iris germanica florentina), 25g Arrowroot (Maranta arundinacea) and a few drops of essential oil, lavender and rosemary work well, but just about any essential oil will do, you can make larger quantities, but I would always advocate making a small amount and trying it before you make a huge batch.
The dry shampoo is really easy to make, you just mix the two powders together with the oil, mix them either in a pestle and mortar until you have a dry scented mix. Or in a bowl with the back of a spoon. Store in an airtight container and use as you would any other dry shampoo, ensuring you brush it out well.
Debs