Quote from MG23:
"As for wreckage washing up, I remember the people who found this flaperon said they'd burned other debris that could have come from MH370, because they had no idea it might turn up there."
It may depend on the debris. Poor coastal-dwellers are unlikely to burn something that could be used to build or repair a shelter. And such items can be sold or bartered.
Regarding discussions of the aircraft's mode of entry into the sea, I've yet to read any proposed scenario that would not have produced considerable quantities of buoyant debris. (Long-time readers of this thread must forgive me for the repetition.)
Any dream of a text-book ditching on a glassy sea, followed by an intact sinking like the Vulcan in Thunderball should be left to movie makers. Given that one flaperon (which may have detached in flight, but we don't know that) managed to sail all the way to beach on tiny Réunion, the chances are that other bits of various sizes are ashore in Madagascar and/or East Africa. Sadly, they may never be found, but one hopes that governments would be spreading the word, and offering large rewards.