In reply to KN:
Granny's pure soap flakes from your local big shop.
I use it for most stuff and keep tech wash for shell jackets etc.
A good tip is to dissolve the flakes in some hot water first and add the liquid to the machine. This way you won't get claggy lumps of soap stuck in the workings.
Also don't use too much or foam will come out of all your machines crevices.