well in spanish the common word is chanklas or chanclas as you want to write it, perhaps in the zone they live they say chankas XD, words sometimes differ a bit from one zone to other here in Spain
LOL, in French, they are called "Tongs" (not thongs, like in australia, apparently... Anyway, as Belgian comic artist Philippe Gelück once wrote... "Flip-flops, they are feet's thongs", which in a funny way is true, so it does take all its sense!)
Edit: on a side note, and for pure information purposes, in Quebec-french, they are called "Gougounes".
Well, in Russian those flip-flops are called even funnier: "tapochki" (I could write it in Russian if I was sure that you could read it). And the name "tapochkast" is quite good...