Not even lab grade filters can filter out aflatoxin.
https://skunkpharmresearch.com/salvaging-moldy-material-2/
"To repeat,
filtration doesn’t remove aflatoxins, so we don’t recommend this process for mold strains that produce them."
I didn't say filter, I said wash. What about this?
"The occurrence of the aflatoxins B1, B2, G1 and G2 in common medicinal herbs and plant extracts was examined. The aflatoxins are toxic metabolites of the fungal strains
Aspergillus flavus and
Aspergillus parasiticus. The method involves the implementation of high-performance liquid chromatography (HPLC) together with fluorescence detection. Aflatoxins B1 and G1 are determined as their bromine derivatives, produced in an on-line, postcolumn electrochemical cell (KOBRA cell).
The aflatoxins are extracted using a mixture of methanol and water and isolated and concentrated by means of immunoaffinity column chromatography. The aflatoxins are separated and detected by HPLC using an RP-18 column and a scanning fluorescence detector. The method permits the detection of aflatoxins with a detection limit of 0.05 ppb and recoveries in a range 70–100% for a variety of medicinal herbs. The method was tested on capsicum, potatoes, stinging nettles, birch leaves, senna leaves, etc."
source
Granted it says methanol plus water, rather than just water, but why even put the water?