Not really. I've dumped 35 tonnes. It comes out VERY quickly. We didn't have a source of ignition in that instance, at least not outside of the can (aka combustion chamber). Nor did these blokes as they'd have shut the engine down. Not a spark to be had then....even so, if you're flying at 300 knots there's little chance of anything coming anywhere near the buggered up engine, or source of ignition, if you like.
From recollection, we used "charlie charlie" a lot when speaking with Calcutta and Mumbai on the HF radio crossing the Bay of Bengal. Not saying it was in a book anywhere, only that it worked. Anyone who flew the Bay of Bengal or the Arabian Sea without CPDLC would well recall the difficulty in getting the message across to our Indian cousins. "Charlie Charlie" was merely used to confirm Calcutta's full repeat of one's just-passed position report details. Quaint, by today's standards.
Anyway, well done Qantas. Would it be rude to say "down with Bruce Buchanan" in this instance? I guess not....being the mongrel dog that he is.