I start it out straight, add a bit of water now and then as it dilutes, until it is pretty dirty and I start fresh. It works very well, not sure why you would want to use all these chemicals with gloves and chemical filters in a half face respirator for.
The only negative thing I would say about it, is that if you leave the brass components submerged for a while, they darken a bit, but that can be polished off after if you forget about the parts for a week in the soak bin.