My local sewing meet-up group had a meet-up where we did discharge dyeing. The meet-up’s leader was not an expert in discharge dyeing, but was much more experienced that the rest of the group at the discipline. She also prepared for the meet-up very thoroughly. Every attendee got instructions, materials (gloves, goggles, respirator, bleach, bleach thickener, brushes and toothbrushes and miscellaneous implements with which to apply bleach, various objects for use as stencil). She also had everything set up and ready to go: tables, two buckets each of first rinse water, bleach stop, and final rinse. We got going in no time. It was a lot of fun!
The main thing that I discovered is that it’s fruitless to try to achieve a sharply defined design. Without some sort of resist, such as wax, as used in batik dyeing, the bleach would eventually bleed out and blur any design you have in mind. I supposed the same is true with fabric painting: unless the bleach is actively prevented from spreading, it will.