My bro is really artistic and I am getting him some paint pens for his birthday because he has been wanting to draw on our boards since we both have blanks. My question is, is there any safe cleaner to use to really get all the wax off, and I dont mean just waiting for it to melt in the sun. It really has to be clean for this to work well. Ive heard paint thinner and other suggestions, but that seems a little rough especially on a fiber glass board. Thanks for any help.