Get the non-removable labels. They will stick! A pain to get off if you ever want to use the clearo for another flavour, though. Still, you won't have to worry about which flavour is which.
It's what I do. Removing the labels can be a pain at first, but once you get the hang of it, it's not that hard, really.
If you do want to remove a permanent label, you can do so with nail polish remover, rubbing alcohol, or vinegar. They can damage certain plastics, so it's always best to test them out first. If you have an old clearo that you are planing on throwing out, it would be a perfect test subject.