pvc tubing with caps on the end some screen and driiled holes in the cap.any home improvement store. 2 male caps adptors, to caps to fit the male cap . some pvc tubing ,1"1/2 is good.drill a bunch of hole in one cap . put in screen into cap. othe cap one hole to match butane tip.freeze herb ,grind or chop it.fill it putt on caps . and extract. do this outside!!!!!!
Shibby is right, stay away from the PVC. Butane is nasty stuff and probably eating layers of the PVC when you extract. Use copper or stainless steel, anything but PVC.
With the price of O'keif's BHO tubes (which I use) you should get one. 40 bucks and your set to go. Well worth it if you have trouble getting supplies.