Drawing and Painting

Does anyone know of a good food grade sealant that is dishwasher safe. I have some metal water bottles that I thought the children or at least Alia, might like to sand off the image, it's just the brand name of the water, and using Posca Paint Pens design their own images, but Posca pens aren't food grade so I need some kind of sealer I can put over to the top to make them safe.

I know many people say to use one of the Mod Podge range but that hasn't actually been found to be food safe, it would need FDA approval in the US. I want something that definitely is food safe and preferably can go in the dishwasher. I don't mind if you need to brush it on or spray it on.

Maybe also I'm searching incorrectly I keep searching on google and Amazon for Food grade sealer or food grade sealant, but a lot of the time I get the kind of sealants like you would put around a sink to seal the gap between sink and countertop, and ones that would fix a crack in ceramics. I need something that goes completely over their art work so there is a protective food safe layer between their lips on the bottle and the paint.

Any info would be helpful, thanks x