I don't think there is really any risk with getting the shelf too wet in the process you describe but I would say one of the reasons we scrape damp is to control the waste material coming off of the shelf. While not a toxic concern it is important not to load your drains with it as the sediment could cause blockage. I'd also be very careful scrubbing the shelf with a hard abrasive like diamond as that could lead to divots and unevenness in the surface. We stick to green scrubby pads. Finally, I don't know that there is any value in drying your shelf *before* you prep it as it crucial that you dry it thoroughly after the shelf primer is applied. We use a 20+ minute hold at 500˚F with an ajar kiln door and then a cool to room temperature to insure the shelf is well dried. If you haven't already, I invite you to drop in our Facebook community page where we have a good size group of folks exchanging techniques and inspiration. facebook.com/groups/BullseyeGlassCommunity/

Tonia, Those scrapers are commonly found at hardware and home stores. They're usually with painting prep tools as razor scrapers. They have replaceable blades of a width generally between 1.5 to 4 inches. The one we're using is ~2 in. wide. Pasted below are links to a few similar options. Thanks! 2 Inch Metal Paint Squeegee, 2-in-1 Razor Squeegee with 40 Metal Razor Blades www.homedepot.com/p/2-Inch-Metal-Paint-Squeegee-2-in-1-Razor-Squeegee-with-40-Metal-Razor-Blades-B095NMFMDH/321685737 Ace 2.25 in. W Steel Dual Edge Butterfly Scraper www.acehardware.com/departments/paint-and-supplies/painting-tools-and-supplies/paint-scrapers/1499482