Straight off the Briggs & Riley website: "Ballistic nylon and nylon bags which are dirty and/or dusty can easily be cleaned with a soft, damp cloth. For stains we recommend using a mild laundry detergent and warm water. Adhesive lint brush rollers work great to remove lint, fuzz balls and dust as well." Although not mentioned at B&R, many sites suggest that if you treat a stain by using soap and water, wash the entire panel not just the affected area.

I'd be a little cautious about using vinegar. Although I use vinegar a good bit in cleaning around the house, it is an acid. I've found applying a soap and water solution with light brushstrokes from a toothbrush can get at dirt that seems stuck in the weaving of ballistic nylon. If I ever considered using vinegar on a bag, I'd make a very weak solution and apply that very carefully.