Bri, Sorry can't help you but just a thought and I know it's not ideal. But if you could prevent anything entering the sd card/slot (not easy in itself) could it be silicon sealed? The silicon 'blob' should release as a lump if required. I guess that this solution would only be suited to a RA which you intend keeping as your own.
My RA is still going after all these years and does sometime become a bit unstable with losing the screen positioning but it's not quite dead yet..