What, are you the type that wanted a new sink so you could make your own marks? Sounds like the price was right, and no, most paints will not stick unless you do a ton of prep work, and any paint you use, if you go that route, will be less durable and stain more readily than the original plastic. As for the tray cleaners, they will turn silver "stains" back into silver haloids, which you can then fix or bleach to remove (BE DARN CAREFUL TO FLUSH THE SINK WITH ABOUT A MILLION GALLONS OF WATER AFTER YOU CLEAN THE SINK AND BEFORE YOU BLEACH IT), if it is "tar" from color processes rather than silver stains, Lysol toilet bowl cleaner might get most of it off. I never bothered with my old sink. My new sink is stainless steel and shines up right purdy.