Residue was and is a concern.
I power washed mine and then blew off as much water as I could with my compressor. I figure heck minor rust isn't a problem with the Zero Rust so I didn't mind using water.
The fellow told me when he was doing it that he could inject water to keep the dust down.
After two days of rain - there wasn't a hint of mess, unlike sandblasting. I still get sand from under the dash when I slam a door five years after I completed the Canary.
I'm hooked on soda blasting and ZR. It's a perfect combination for us "do it yerselfers".
