I don't know about the Mata Chica sandal walkway, but I do know that when I was in Coz during Mitch, I've never seen so many sandals and thongs littering a roadway in my life. Shoe, coconut, sandal, coconut, coconut, thong, coconut, log, sandal, thong . . .and on and on and on.
We had one pal with us that had forgotten to bring thongs/sandals with him from home. He wasn't with us on our adventure that day, so we harvested a "pair" for him.