I use well-seasoned cast iron and carbon steel pans for the better part of my cooking. To clean them, I’ve used the same bamboo wok brush than I bought at a corner market in Sacramento in 1990. I’ve been thinking of buying a new one, just so I can phase it in over a few years while I slowly retire the original. It only takes a few swishes around the inside of the pan with hot water (no soap!) and a rinse to clean a pan. In the time I’ve been using it on my iron and steel pans, including the wok I use occasionally, I’ve gone through countless sponges, scotch-brite pads, and those looped-plastic scrubbies that I use on stock pots etc., all of which get pretty hinky once put into use and have to be run through the dishwasher to get free of food particles. It also looks dignified and fine sitting on the countertop by the sink, has just gotten more seasoned, and never needs more than a rinse to get clean. The edges of the cane bristles are pretty blunted by now and a new one might work better for attacking the occasional nuclear cooking mess. On the other hand, it’s gentle enough on the built-up seasoning in my pans that they keep getting non-stickier and shed scorched cheese like schmutz on teflon.
The brush I bought way back when has flat bristles, about 11 inches long by 3/16 wide, and stouter than most of the wok brushes I’ve seen recently in Asian groceries. I can’t imagine that there’s been much innovation in wok brush technology in the last 3000 years, but quality is probably inconsistent on an item like this, even from the same seller. Unless you have access to Asian markets and can shop around while you’re out making your weekly durian run, Amazon has a variety to choose from, all about $7.50 with shipping. The Wok Shop seems to be reputable, but it might be prudent to order a few just in case yours only lasts as long as a good hamster.