Have a look on the WET and FORGET website,a bit on the expensive side,I used it to get rid of mildew/mould on my aircraft,works a treat,used on boat sails,doesn't rot the stitching(never use detergents)one other thing to try is dettol,
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.