Sail Cleaning Solution

I have one year old Mad Snug sails, and love love love them.  Being a lazy sailor and sail quite often, we leave the main sail on the boat, and just roll it up suspended from the boom by 4 wide sail ties.  After 9 months the lower 3' of sail developed some grungy looking gray dirt with some tiny black spots in this lower area, which is exposed to the air somewhat.  I guess I should say that we have a full boat cover that goes on.

I was hesitant to try bleach, etc.  Instead laid the sail down on the carpet, and used a slightly damp magic eraser, just water.   With just a gentle rubbing, all the grunge came off on the magic eraser, which you squeeze out under the faucet.

I realize that magic eraser is just melamine, a mild abrasive of like 3000 grit.   The sails now look brand new.  One thinks that leaving all that crud on the sails tends to reinforce small creases, which are not good for sails.

I plan to repeat this every 6 months.