Cleaning fiberglass boat hull with Spinach

Ever hear of cleaning your boat hull with spinach?
Well, not exactly; the ingredient is oxalic acid, but spinach happens to be very high in in oxalate (oxalic acid), as are Beets, Rhubarb, Cocoa, Kale, Sweet potatoes, Peanuts, Turnip greens, and that's just to name a few... Actually Oxalic acid is found in almost all plants, but in varying degrees, and there's only trace amounts in meats.

Now I didn't know that, nor do I particularly care, perhaps you don't either. But it is vaguely interesting that oxalic acid is also used to improve beer production at many breweries... And we all know that boats and beer tend to generally go hand in hand; so it naturally stands to reason that it must be good for cleaning the hull of your fiberglass boat (the oxalate for cleaning, and the beer for drinking while you work).

Ok.. Let me explain what the hell I'm talking about..
It all began when I came across this youtube video (below) of some guy and his wife (or girlfriend.. or his sister for all I know) were making various attempts at cleaning the fiberglass hull of their trailered speedboat. They didn't have a clue what they were doing, nor did they pretend to. They had already tried bleach, mildew cleaner, magic eraser, green scrubber pads, and repeat efforts, but the hull was just not coming clean.
Finally they bought a 6lb jug of oxalic acid (it's dry granules or powder) for $16.85 (that's the current price), then mixed a couple ounces of it with water and applied to the hull.
It's amazing how quickly and easily the hull came clean.. Now I don't mean the barnacles, I mean the embedded off color, stained, dingy, residue or whatever remains; the barnacles obviously require scrapin. But the point is that it almost instantly made the hull look new.

However, I couldn't help but wonder what they might really be doing to their hull?.. what if that acid was setting up some kind of chain reaction to start deteriorating the fiberglass?
So did a little quick research on oxalic acid, and amongst other facts, discovered that oxalic acid is the primary ingredient of toilet bowl, dishwasher, swimming pool, and spa cleaners..  and get this; it also happens to be the primary ingredient of commercial fiberglass hull cleaners!




A quick browse through boat forums also confirmed that using the method as in the above video
is an extremely effective and economical method of cleaning the hull.
Cost only about $16 for enough of this stuff to last a lifetime.
http://www.soapgoods.com/Oxalic-Acid-p-889.html

I don't know about you, but I'm convinced.