After reading Vovin's Tech, I like the idea of a true A/B extraction, but a Buchner funnel is another piece of gear to buy and it's clunky and adds risk (tip-over, extra handling).
How about using a disposable paper tea bag to contain the botanical material in the acid solution? It's probably less wasteful too, as Vovin suggests you should expect to use multiple Buchner filter papers as they get clogged.
Has anyone tried this?