Looks to me sand or salt is still the overall most effective, reliable*, and cheapest option no matter what type battery. Those extinguishers could come in handy I suppose for certain initial situations. I do have ABC’s up the ying yang all about though so I’m prepared there.
(*Reliable: I’ve had extinguishers fail to operate as expected. Age related malfunction, clogging, intermittent spray, etc. I don’t trust them to work everytime all that much basically.)
Now if I happen to have primaries, lipos, and lithium ions in the same relative close vicinity to one another (same room which I tend to do) and there’s already one smoke house a-commencing I sure as hell ain’t gonna try and figure out WHICH EXACT TYPE lithy or combination thereof is doing all the flaming, gassin, and a smokin. Watt am I supposed to do grab two different chem mix cans and play roulette extinguisher? 
So a good sturdy Behren’s galvanized U.S. made 5 gallon pail, airtight with lid, filled with good ol’ dry sand, stands nearby. That and a small coffee can for more ‘precise’ flinging if necessary.
Yup that’s me. And then after said dump debacle I’m still running away till things settle down. Yeah the cleanup will be real fun too with either method. 