without buying them for so much money in the user shops?

Nope :( They won't go back to the cash shop.

too bad I need a lot of plushies out of them :(

we have a chance of stumbling across items in them from the reward for doing Major Drills quests, it's a small chance, but it's possible.

if you don't mind spending csc the lumineve gift from the CS gives old ci/dp stuffs