You can let some of the mixture remain for later. You dont have to shower with the mixture. You can use it as a hair mask like sanctuary is doign and leave it overnight. You cna also leave it in for a as long as you want then rinse it out. It works the same for me either way.
I use organic on my face as i also have acne scars from pcos. I have used unorganic on my face and it gives me hot flushes dont know why, maybe blood circulation. I know of an excellent product that has cleared my acne and helped control breakouts its called green detoxing clay. It makes my face even coloured, baby soft, stops my acne from breaking out and has cleared old ones. I buy mine form the health food store but i found the website on the package here it is http://www.livingvalley.com.au/shoponline.htm
I dont know if they sell to overseas though. But this mask is a godsend.