I have tried every recommended concoction and also store items to rid the black mildew on my non skid areas. The liquids do seem to reduce the mildew to a stain effect, however getting the blck out of the perforated non skid skin has become almost impossible. Stainless steel brushes etc etc..do not remove the mildew.. Is there a work all type of recommendation out there..The non skid is poured with the hull and is still in excellent condition...I do not want to lose the non skid, nor paint over it and render the non skid non-effective...Thank you for any and all heads up....