i can confirm they do work. i cant see your photos but ill assume its a filter-paper accepting buchner, and a vacuum hand pump.
DO NOT USE SINTERED GLASS
it will clog, forever, its a pain in the ass to destroy organics in the frit, and any calcium sulfate, or silicates that go in there, such as what some tap water precipitates out, those are more chemically inert than the glass. Filter paper on sintered glass also wont work well. you wont get a perfect seal against the frit and paper so some stuff will suck through around it and the edges will clog and permanently contaminate anything subsequently filtered through. this may or may not matter but, fritted glass funnels are not meant for these sorts of organic filtrations.
personally i use a water-aspirator, you push water through using garden hose, and it will pull a vacuum so strong you can boil water at like 30C if your water pressure is high enough. just gotta be careful with strong acid fumes, the cheap $15 aspirators are made of aluminum.
I have 2 different hand pumps, both can reach up to -650mmHg, i think the max vacuum is -720mmHg, if im wrong, its just, like almost 90% to absolute vacuum. so basically, yeah, the hand pump will do anything you want to do, make sure you get one with a vacuum dial.
A trick i have applied for devastatingly fine filter-clogging substances is to thermal-cycle them a little bit, i forget which, perhaps some kind of hydroxide or oxalate, but the first precipitate is fine and mere milligrams out of the 250-400g to be filtered would clog the filter. heating to whatever temp it begins to dissolve, then stopping and chilling, and cycling a few times, and in the case of one, just boiling it for a while assuming it cant all dissolve, results in crystals forming, prefferentially on existing precipitate. when the crystals grow they cannot pack together as dense, and form sediment porous enough to vacuum filter. tannins may not be able to be filtered like this since my vacuum filtered tannin-cakes tend to resemble soft chocolate, however, larger crystals of the waxxy tanins will still settle much quicker, if fine enough and fluffy enough its possibly they might not settle properly at all.
The use of celite, powdered cellulose, sand, and combinations therof also greatly assist vacuum filtration. Celite is the main one though. diatomaceous earth is the raw product celite is made from after being acid washed and baked, dont buy diatomaceous earth unless its specifically made/sold for filtration purposes, until processed it also clogs filter paper like a mofo.
If you have the means to safely do so, try a long column centrifuge. literally anything that can smoothely spin around without sloshing and has as great a fluid height as possible, will quickly cause things to settle for high-speed decanting. the addition of sand or porous media where your tannins will be pushed into and wont easily flow out of, may or may not help.
lastly, there is some acuminata no-goo teks, or other teks, look into them, there are techniques for keeping tannins in the bark. they amount to gentle ph control, use of salts, and i think some specific treatment when producing a concentrated acid soup.
