My boat seats have embedded black and greenish yellowish mold on them how do I clean it Have tried many different things but it only seems to clean the surface mold not the embedded mold.?

use very fine steal wool and a color safe bleach i was told about it from an upholster i knew and it worked great good luck

This worked for me:

Go to mdrAmazon.com and find their Mildew Stain Away.

You spray it on. Brush. Spray some more. Brush. and the vinyl looks like new.