Hello. I haven't tried doing this but I would look closely at the ingredients list of the store bought pickles. They often have a preservative in them which could undermine your fermentation bacteria. Also, I would suspect that the high acidity might be too much for the little guys to ferment in. If I were to try this, I would remove the pickles, rinse them and submerge them into a populated brine. But that's almost more trouble than using fresh cucumbers and you still might have the preservatives in there.
On another note, I've tried oak leaves to help keep the skins crisp and had some success.
Good luck