[dsraven]

yup, I would blow it off outside and then wash it with some of that prewash/soak at the car wash-still no touching, it seems to take stuff off pretty well with no contact. then let it dry without touching yet and see what kind of scum is left, if any. are you able to take it to the car wash or have a pressure washer at home that can run the soap through?
I found out the hard way about grinding sparks too. had a welder fix a headache rack and the guy never covered anything. sparks in the glass and paint. you also need to be careful if the door or window is open because the sparks burn in to the cluster lens too, and the seat covers etc. I use an old beach towel with a small flap sewn in one end. it flops over the seat well and also keeps my greasy coveralls off the upholstery. an old towel over the dash works too. no dust down the vents to blow out at you when the key is turned on plus lens protection for the cluster.