By "pastillas de encendido", were you talking of barbecue fire starter cubes? Oh, my! That's an aberration of the language, and an aberration of the barbecue (needing more than one match to lit a fire).
"Pastillas de encendido" are a part of the "sistema de encendido" in a motor vehicle using fuel and explosion started by spark. The other ones are "pastillas para encender", no matter what they say and use in a lot of places. They are the same nitwits who speak of "modistos" and "industria alimenticia" everywhere and now and then drop a "producto alimentario". They are hopelessly lost (I always wondered if the "industria alimenticia" provides a lot of iron, "mi primo, el tenisto" may need it
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