crushing glass into hypertufa

I read a book from the library a few years ago which talked about putting your mix into a bucket along with broken bottles and use a board to smash it down until the glass has become just small pieces then molding it....after it's removed you use a disc sander and ground down the sharp stuff.....I can't find the book & the library can't find it on my record....do you have any suggestions? I'm also wondering how you determine how much mix you need per person? I have 9 coming on Tuesday to learn together, I'm supplying the Portland cement & vermeculite & sand.....I've done this twice: one successful one just a wet mess....please help.....Thank you