Everybody in harsh noise has either a DOD death metal, DOD Grunge, Boss bass overdrive and/or Boss heavy metal for the most part. Do not buy one of those immediately though, this has become kind of stagnant for the genre even though I have two of those aforementioned pedals. I have no idea what the RSH 01 is like, but I personally find the bass overdrive after a DOD fx25 envelope filter decent if the sensitivity is low on an amplified object. I usually need a distortion before the envelope to flatten and manually control the filter when I want to, preferable something that has range in gain and EQ (tone).
a little bit of phase effect to repeating samples goes a long way, having it on full blast makes it sound stupid to me though.
sometimes people put springs on amplified objects to add a longer sustain of a lower signal before it feedbacks into itself and it does tend to have more interesting feedback changes. I prefer double sided mounting tape when I use contact mics on things, its fairly cheap and everybody in the store knows where it is from making displays with it, though get the indoor kind since when it's too strong the mic fall apart before the mounting tape does.
Feedback loops/no-input are a heck of a lot more satisfying if you have an equalizer in the scenario, otherwise you really don't have much of an say to whatever frequency it will be. I'm tired of them frankly, but I did those things for 8 years so maybe its just me.
