Cool story, and good to know. I wondered if it would work for water but I hadn’t read the info enough to know. That’s good timing because I’m thinking of taking out my water softener or rather water not-softener, and I wanted a way to clean out the water and salt to make it easier to handle.
Sounds like a decent plan to me, bail out what you can, then bust out the shop-vac. That salt would be a killer on the vac alone!
For static control I removed the plastic on the outside around the wire in the hose (manufacturer recommended this) (only have to remove enough to solder onto the wire like 1/8" wide strip about 1/4" long with a box cutter. This I attached to a silicone insulated (super flexible) wire I ran along the pipe and connected it at 3 points along the hose (because I don’t know there are no breaks inside that hose). Those run to a ground pin on the same circuit as the x-controller (no ground loop) and I used copper tape from Adafruit to go through the dust deputy to connect all that up (supposedly that plastic is conductive but I trust copper). It has be static free.