In my experience Hoover is certainly used as a generic term by a lot of people. I haven't heard biro used generically though, but people have asked me for a Bic, meaning cheap clear plastic ballpoint. Maybe that's regional?
In Germany particularly, Karcher is used for any pressure washer and I've heard my (English) parents use it as a verb, even though theirs is a different make.
I don't think a particular brand can engineer this kind of adoption (I'm looking at you Sarson's and Walls!),
Cashpoint is another one that gets used for all holes-in-t'wall. J-cloth has probably crossed over too.