Sure they do own many companies. I just dont think its impossible, as I steer clear of anything nestle. Sometimes I grab something new and sounds interesting like the Vegan products by Gourmet Garden and just putting it quickly back as I saw nestles logo printed on the back.
Also not only are there those lists, but we all have an internet enabled smartphone nearly always with us right? So check the label, see its hierarchy and decide then.
Because all those products en.wikipedia.org/wiki/List_of_Nestlé_brands are made by “companies” that on first look are not “owned” by nestle even though I always saw their huge logo somewhere on its packaging.