Lol I have a specific bottle labeled "junk juice" I have no idea why I bother, I doubt it will ever be anything vapeable, but I do keep it nonetheless lol. Also, if I'm getting juice out of a cartos I'm tossing anyway, I take the filler out and stick it in a 5ml plastic tip syringe and squeeze the heck out of it, it seems super effective.
Bear in mind I'm a newb. Now that in straying from the newbie forum I feel like I should come with a warning label lol