Does anyone know whether there are any "safe to chew/suck" crayons or baby markers? my 15 month old puts everything into his mouth and I'd like to get him some colours so we can start drawing. he tends to try and eat crayons at toddler groups so I spend the whole time pulling them out of his mouth. ive seen crayola do washable first markers but can't see online if these are ok for babies to put in their mouth. Does anyone know?