BIX problem
 

The paint on the in-outlet is "melting" and is dull. I can rub it of
with a cloth and i get some black goop. I'm using demineralised
water and waterwetter. Is this normal ....?

doesn't sound normal. my BIX is shine black still (same fluid, & yes, i spilled some on the BIX on accident too). it sounds like you may have inadvertantly got some chemical on it that is eating at the paint (i've seen enamel "melt" after petrol was accidentally oversprayed on it). you probably won't need to use black goop since you don't have a leak, unless you just want it black again without having to remove & repaint it (which i wouldn't want to do either BTW). cleaning it & brushing on some gloss black enamel would also be easy, but not as pretty as spraying on a new coat.

black goop = melted paint
no other chemicals used