regular old cheap white vinegar i buy it in the gallon jug. works perfect i let my 6 year old do the sprayin and she sprays her face her brother along with everything else. no chemicals and its cheap. so im like have at it.
X3 on the vinegar and water. We do Eagle lake in Nor cal every year and the high alkaline water really spots the boat badly. As you wipe the boat with a 50/50 mix of regular white vinegar and water you can feel the boat go from rough to smooth. just follow up with mild soap and water, rinse well and be sure to re wax
X4 for vinegar and H2O. We call it V2O! Works great, and my Malibu dealer recommended it. All of those other products are entirely over priced. As stated earlier, just make sure to wax every now and then. I've been told it strips the wax.