First of all the soap smells very zitrusig or sand thorny. I had that same smell a shower buckthorn times of Weleda. I like the smell very much, because it fresh and fruity but not smells Kloreiniger!
I have cleaned my brush so as follows:
Make brush wet only under running water
Brush then rub in the soap short and using a circular motion, thus the soap begins very soft to foam
Then wash brush again with circular movements on the palm
This principle has ei worked well all my brushes and I never had a second time take soap to the brush to get clean. I could wash etc. without any problems waterproof eyeliner, waterproof cream substances, eye shadow, concealer, mineral powder. I especially enjoyed my record all the weißborstigen brush (Stinktierpinsel similar) also very good, and above all with a single time soap have become clean! This has, according to verwedetem product, not even worked with my MAC Brush Cleaner (who incidentally viiiiel more expensive).
I just washed all my brushes with what to most current are no less than 61 pieces. And in the soap is not even a depression to see, which is why I think that it will last forever.