They both will have thier own problems.
Heatshrink- batteries don't like being hot. The could swell during the shrinking.
Dip- getting that gunk off will be your big problem. If you don't get contact, or can't get the battery into the battery well, you might as well not have them.
CR123s carry nicely in a paintball tube, and should carry nicely in a shotgun choke carrying tube. AAs, find yourself some 1/2" tubing with end caps. The "speedloader" tubes for blackpowder should work well enough, but they might need to be trimmed.
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-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.