Man, this thread got lost and I couldn't find it.
I washed mine in a bucket in half bag batches.
Don't wash it, lightly rinse it once and put it in the tank (if you wash it you are washing all the things you want down the drain, and should just use standard gravel instead). Fill tank VERY slowly! Make sure you have a thin gravel cap on top of it to allow the fish to do their thing without disturbing the stuff.
I don't think that's true. We use fluorite because it has a high CEC, or cation exchange capacity. Not because there's anything special in the fluorite, although I do concede that there are some trace minerals and metals (iron and such).