Just as we Brits use aspirin, escalator, biro, trampoline, thermos, sellotape, catseye, dormobile, durex, bubble wrap, photoshop, stanley knife, armco, JCB, fibre glass and lots more trademarks to describe generic products so do the Spanish.
So Mistol is a brand of washing up liquid. I bought it that day, just grateful that I'd found the stuff. It's good stuff, it smells nice, it has lots of flavours. There is a little dodge, a little marketing ploy, with Mistol though. It has a really wide spout in relation to most other brands of washing up liquids. The liquid gushes out and gets used up very quickly. I've decided it's an abusive design and I've bought Fairy again the last couple of times.
Obviously I don't know all the Spanish trade marks that have become household language but these are some of the ones I've noticed. Actually as I worked on the list it became so long as to be boring so I cut it down. Bimbo is used for sliced bread, Danone for yoghurt, Avecrem for stock cubes, Casera for a sort of lemonade often mixed with cheap wine, Bic for Biros (see how whimsically I write?), Dodot for nappies, Rimel for mascara, Kleenex for tissues, Táper or Túper (mispronounciation of abbreviated Tupperware) for plastic food containers and Post-its for, well, Post its.
I suppose these words change with age and possibly with location. I hoover up (not often enough according to Maggie) but I don't think it's a popular generic term amongst younger people or amongst people from the South of England. I had something similar with aspirin, aspirina, which is a Bayer trade mark. I asked for aspirina in a chemist's in Yecla. The chemist asked if I were sure and produced the trademarked brand at, say, 4€ and a generic at well under half the price. I went for the cheaper brand. I only use them to ward off heart attacks after all. The chemist obviously thought this was all a huge joke and spent the next few minutes coaching me in the pronunciation and rhthym of ácido acetilsalicílico, acetylsalicylic acid. Years later, now fluent in ácido acetilsalicílico, a chemist in Cartagena took me to task. "For God's sake, don't be so prissy, say aspirina," he said.