As I posted yesterday, I just purchased a used Orange AD30TC combo. The grill had some stains on it, so I got a soft-bristled scrub brush (made for car interior detailing), and I scrubbed the grill gently with warm soapy water (I used dish detergent, because I wanted something that wasn't too abrasive). The results were pretty good. The stains are gone, but the grill dried just a little inconsistently. Now the grill has an ever-so-slight mottled look to it. It's really, really slight, and I doubt that anyone, even anyone familiar with Orange amps, would notice it, unless I pointed it out. I am curious if anyone has any experience cleaning the grills on Orange amps, what their methods are, and what the results are like.