[akaigxfan]

Hello, if this is a really stubborn mark, try a small amount of acetone free nail varnish remover. I've always found this to work, although it doesn't say anything about it on the forum. TBH alcohol isn't much of a cleaner, although that is all they'll tell you to use, or meths. I've also found a small amount of Brasso on a cotton bud to remove stubborn stains or corrosion. Hope this helps. Dave.