I have an 08 196 whenever I have mildew, I have always used 1/4 bleach to water and a brush to clean with. I put it in a spray bottle spray, brush and rinse. I only starter to replace 3 covers of my interior 3 years ago that's 12 years before I had to recover. Granted my interior is off white. If you know me, I keep a clean boat and live in the Florida sun about 1800 hrs on my 196