Now this is a challenge.
If you know anything about sailing and sails the general advice is if you have to clean your sail (and this is really only if you have to) then use a brush and some warm soapy water. Anything else will destroy the sail and they are precious. But we want to chop them up and make them nice and bright. yes, we considered industrial bleach and other chemicals, but this somehow doesn’t ring true to a recycling company.
I must confess that we did try some hard strength chemicals, but what actually worked best in the end? lemon juice and bicarbonate of soda! Brilliant. Not exactly slick manufacturing process, but we are not about that.