Yea, came up good in the end. I figured just water wouldn’t be adequate, so used a strong TFR mix which still wasn’t adequate. So bleached it. I’m not entirely happy about using bleach on solar panels because it doesn’t actually get rid of the debris, just makes it translucent. The crap that remained after the TFR was white after the bleach treatment, so that didn’t look good. A good scrub got rid of that.