Multiple 'et cetera' use [closed]

Sometimes people say "etc., etc." at the end of a list to whimsically suggest many more items. Is this grammatical? Is it acceptable in a professional or academic context?

Solution 1:

Doubling words for emphasis is common in English - very very common in fact. This is despite the duplication having no semantic role.

A list finishing with etc. etc. is slightly different in that it's not exactly for emphasis, but to imply many more items, trailing off ad infinitum.

As regards usage, I wouldn't write it in a paper/thesis. I would be happy to use it in a talk, even on the slides. If your overall presentation style is at the formal/dry end of what I've seen, this might not fit so well, but if you aim more for a storytelling feel it would be absolutely fine.