Knurl has mic'd up and played all kinds of customized welded monstrosities, typically approached in performance with a metal prong or two. Some of these things could be pieces of art I suppose. Not sure what happens to em when he gets bored. One memorable peformance he gave was an outdoor one, hurling boulders at a very long, er, length of chain-linked fencing. For pure physicality, though, his double-dildo'd assault-on-a-toaster phase delivered the goods every time.
Kiyoshi "white gloves" Mizutani, aka the Noise Scientist, brings new "gear" to every show. Basically, discarded metal scraps, hubcaps, long steel bars, etc, he finds in the immediate vicinity of the venue. The performance generally involves an unhurried, semi-bemused exploration of feedback in relation to the various objects, speakers, the performance space, and audience members. It looks, sounds, feels, and smells like a kind of field trip with the wacky science teacher, you remember, from your sophomore year in highschool. Maybe a tad heavy on the ozone.
There's an excellent harshnoise show performed regularly at the local science center. They close all the doors, turn off the lights, and instruct parents to cover their children's ears. They then blast a sheet of glass with 20,000V of raw electricity. A few times for good measure. Kids are crying, moms exclaining, "Sugoi desu ne!" Pretty funny stuff. I used to think it was hilarious that they did this every day, five times a day, all year, but was disappointed to later learn that it is only done on the weekends. I wonder if the energy saving policies following the nuclear accident have put a dent in this little show.