I could be wrong but from what I'm reading the buildup is actually Aluminum Oxide. Aluminum oxide apparently forms in picoseconds on non anodized aluminum surfaces such as the ring on the top of the volcano, so I don't think short of totally somehow blocking off the top of the hybrid and still allowing it to function that they will get rid of the aluminum issue.
My materials education is limited, but I do know most (if not all) "safe" metals will have an oxide layer. Without an oxide layer between the metal and the outside world, the metal would rust (which wouldn't be safe!). For example, stainless steel has a layer of chromium oxide that protects the underlying steel from rusting, and we tend to consider stainless steel to be safe.
I'm not trying to say that the oxide situation isn't an issue (I honestly don't know), but that's not what I've been talking about.
The "dust" in the picture I posted earlier is made up of tiny pieces of the aluminum heat-ring/chamber that have broken off due to friction between the twisting metal pieces of the Hybrid. If there's an oxide layer that's rubbing off, I'm sure there is oxide there as well (there would have to be), but this dust is physically too large to
only be oxide particles.
Without any friction, I believe the oxide layer would pretty much stay put (don't quote me on that, as I said earlier, I only have basic materials knowledge). Right now, my main concern is the metal wear particles that are being produced every time the chamber is attached to the Hybrid.