My wife is allergic to X. It was recommended to me by an allergist to feed X to my toddler 3 times a week,
The problem is my toddler likes to kiss us on the cheek, and we share similar food (e.g. an apple). If my toddler had traces X in his mouth, it might cause my wife to react when he kisses her (it has happened before when I had traces of X and I kissed her).
My toddler isn't old enough to know how to brush his teeth or rinse his mouth. What are some ways to ensure my toddler doesn't cause my wife to react after consuming X?