Not sure if this forum is any good for this - but I need to find a decent retrobright solution (not a paste as it causes streaks + marbling). I have so far tried sodium percarbonate (Vanish Oxi Action) as recommended in the link below but unfortunately it sucks. Its worked about 75% over 2 days in the spring sun and mixed 3 batches. I've almost used 1kg of the stuff and its not cheap, or reusable. Link: http://members.iinet.net.au/~davem2/overclock/Retrobrite.html So I think a highly concentrated solution (liquid) of hydrogen peroxide would work better. Though looking through priceline... I have no idea about what the consistency is like or its concentration. I've asked my local chemical supplier but its not something they carry. So what would you guys recommend in 2018?