I won't use a metal bristle brush. I have a Nylon job with a scrubby and a scraper. I don't use the bristles...
I have on order one of those bristle free brushes that should be arriving today...
I am not really super paranoid, but I am also not into taking stupid risks...
Now for regular / each cook cleanings, I simply heat the grill up and get it good and hot, and then give it a quick scrape with the scraper, and then a scrub with the scrubby pad side of my brush. NO bristles! Call it good. But when it just gets to be too much...
The bottom segment of a plastic barrel is a great idea, but I have been using a heavy duty garbage bag laid over 2x4s to make a frame kind of thing. Sort of like lining a truck bed with a tarp to make a rolling pool... Anyway, put the grate in, soak it extensively with simple green, or other environmentally friendly cleaner, and let it soak. Scrub with a green scrubby pad rinse, rinse again, and then rinse once more...
Rinse down the black gunk from the driveway and throw grate on the grill ready for the next round of major cooks.