simple. find a heavy gauge pvc. glue a cap on one end. glue it tight. i've heard stories of bursting extractors. they are usually big ones and you end up covered in sticky ground trim that does not come off. put a thread fitting at the other end screw on a screw cap drill a few holes. done. once again make sure it is glued well. please do not get hurt. filters are a little trickier. i have not tried brown paper bag yet. i take a potential piece of paper and place it over my lips and suck thru it. you should be able to draw air thru.
i have personally never made my own. my suggestions on this matter are pure hearsay. i don't see why it wouldn't work though.
extractors are available at:
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