The need to educate a person not to waste food or about one's privileged life has absolutely no dependence on your example, nor is the latter inherently about racism, unless that is your actual motivation, or a real life counterexample. You just pointed to a convolution of stereotypes about a continent, which is quite the irony when you wish to teach about privilege.

And your lame counter-accusation is basically a common rebuke of your average actual racist.

More over, the original “don’t waste your food” trope hides hypocrisy, because those parents don’t necessarily care about African children. They care about cleaning up. Some actually care about Africa, but it’s disjoint from keeping kids clean.