Did not see this thread for a while, but then caught that my name mentioned was mentioned. So, The toxic compound in the above-ground parts of the root is Piper Methysticine (PM), not FKB. FKB is in tudei, Isa, wichamnii/wild kavas, and is found in the root stock as well.
As per toss-and-wash - what I have found is that since root tissue does not digest, you get a gassy bloat. Additionally, it seems (or so, I theorize) the fines (particulates) function to break the surface tension of the gas bubbles in your GI tract, making the gas/bloat near impossible to pass. IT gives me a serious stomach upset. Now - to be crass - if I take a simethicone, I'll fart the bad feeling right out, but who wants to have a nice mellow feeling, or be around someone with a nice mellow feeling, and listen to that?
So, I am not a toss-and-washer.
Cheers!