I only use cheapie lighters now that my Colibri has disappeared, and only do refills with the occasional purge.

But I have learned my lesson on butane when I had to use some unknown "tobacco" shop brand when I was in a pinch. The lighter didn't work very well after awhile of use with that butane, but I think I ran a wire brush over the nozzle, and it worked better. Also did something to try to move a nozzle with the square end of the brush, but ended up cracking and breaking the deflector material. Works like a champ still to this day. Did I fix it?...can't say.