hasn’t at least had a McDonald’s shake or something
What they’ve done in the past is irrelevant. If they choose to forgo Nestle products from this day forward, then it is possible.
Are you legally mandated to go shop at the grocery store? No?
I never argued that one was legally mandated to shop at a grocery store. Whether one shops at a grocery store or not, one can consult a list and therefore not buy Nestle products. This is quite simple.
Then why would you posit that response?
Just as an example of how it is possible not to buy certain products, regardless of how ubiquitous they are.