If you want to bring an old pair of your kid's Crocs back to life (or if you want to hand-down an older pair to a younger sibling) wipe them down with some Armor All after you wash them. They'll go from that dried-out dull to an almost-new finish. Crocs makes something called "CrocsButter" (which comes with a sponge applicator that in my experience dries out rather quickly) but chances are you've already got some Armor All hanging around in the garage. And if you don't, at least you can spend your money on something that might come in handy for other stuff.
Dad Tip: Crocs + Armor All
in Clothing