OK DoingItForMyself, here it is:-
All you need is to buy some pure castile soap in liquid form, I would strongly recommend Dr. Bronner's Baby Mild liquid castile soap as this is the one that I use but I assume that any castile soap would work as it would be the same principle. It's just I know that Dr. Bronner's is an all natural product, you can get it from online companies such as 'big green smile' and 'www.lucyrose.biz' (sorry, not sure how to link). I use baby mild as it is non-fragranced but they also do a tea tree fragrance which may add to the effectiveness, who knows?!
Castile soap works on lice because they have an exoskeleton which the soap dissolves, thereby killing them. It works the same way on anything with an exoskeleton such as ants and greenfly, so could be useful elsewhere too!
Anyway, the method....
....make a mix of the soap and some water in a spray bottle, 1:1 ratio. You then need to thoroughly soak the hair with this solution, rubbing into the scalp as you go.
Word of warning though, as this is pure soap you must make sure the eyes are protected and that the inevitable run off doesn't get in the eyes because it will sting.
Also you will need to cover the floor under where you are working with a towel and wrap a towel around the shoulders as the solution does tend to drip, especially once there is lots on the hair.
Once you are satisfied that the hair is completely covered and soaked with the solution, and that you have rubbed it in well, just wrap a towel around it and leave the soap to do it's stuff. Leave on for at least 10 mins. I usually give it about 1/2 an hour.
After this time you need to thoroughly rinse the hair of all the soap, as a bonus it will have cleaned the hair too!
When I rinse I do it with a shower attachment over the bath with the plug in, this way you can inspect the water afterwards for the dead lice.
They are quite easy to spot as little black specks in the water.
To be sure you are getting rid you need to repeat the above every 3 days for a couple of weeks. Slightly annoying but nowhere near as hard work as the pain staking combing with conditioner which, btw, I feel is the only other effective method to use.
Put simply; Spray on, rub in, wrap in towel, leave for 10-30 mins, rinse off, job's a good 'un 
HTH