I finally got around to a video of the latest solenoid I’m using in my Contra. I used 2 different ones before this, both were quieter than this one. I think this one is a keeper.
Switches: 80g Aliaz lubed with Tribosys 3204
Solenoid: https://www.adafruit.com/product/2776 (pay attention to the sample circuit that uses a power transistor, you’ll want to do that)
Some sample code, how I control solenoid: https://github.com/walkerstop/qmk_firmware/blob/mike/keyboards/contra/keymaps/walker/keymap.c