[pwd72s]

I just wash my shop vac filter with a hose shutoff nozzle twisted to a stiff spray. Spray the outside first, being sure to get between the cleats, then spray the inside, giving it a backwards flow. Then hang it to drip and air dry. Usually buy filters 2 at a time, so I'll always have at least one ready to use since the drying can take time.

After washing the filter, into the house to clean my glasses of the overspray.

Don't see how a car wash vac would hurt anything. Nothing ventured, nothing gained.

(edit) I have extensions and a kit that allows me to clean the house gutters with a shop vac while staying on the ground. At my age, don't trust my balance on a roof.

It's quite an upper body workout, but it seems to work. All of the vac gets a washing after that one...pretty messy job. Natch, keeping water away from the vac motor, but everything else is washable, including the inside of the hose.