Years ago, one time on a trip to London, I went alone to a play - don't remember what play but it was a comedy. The whole audience burst into laughter at one character's line about using a Pifco. I didn't know what that was. I asked my neighbouring seat-mate, a stranger to me, what a Pifco was. She leaned over, very close, and whispered, very discreetly, "It's a small electrical appliance," The brand name stood for the thing. That doesn't happen often, not to stick, and Brits do it more often.
They say 'corn flakes' for all cereal. They say 'Hoover" for vacuuming and also for devouring food ("I hoovered it up"). I guess the closest to that usage is in Newfoundland. When a Newfoundlander says fish, he means cod. All other fish are identified by their names.
Some brand names make it into a generic identity but it doesn't always last. Xerox used to mean photo-copy, no matter what brand was used. Not any more. Thermos is still, I think, in wide general use but vacuum flask or bottle is competing with it. Kleenex used to be king but there are lots of other brands, including generic ones, that are identified as facial tissues, including those cute little purse packs labelled SNIFF or with Xmas greetings on them. (Does anyone, except perhaps the Queen, remember handkerchiefs?) Oh, and then there are Post-It Notes and Scotch tape, both from the same company, and they have stuck, if you'll pardon the expression. I'm wondering if the indefatigable rabbit is beating out other batteries. Product recognition must cost a fortune.
Is Coke synonymous with a soft drink, a thirst quencher, a happiness symbol? Okay, what about water? Are we going to start identifying water with the safest, cleanest potable liquid we can find? buy? Oh my.