In the absence of any suitable material with which to create a roach, a make-shift 'filter' can be made by pinching the joint first one way, then the other adjacent to one another.
I say 'filter' with the most relaxed paramters to the term.
2. Put your two index fingers next to one another on the joint.
3. At the furthest in finger, pinch the joint vertically.
4. At the point of the finger at the end, pinch the joint horizontally.
5. Smoke em if ya got em.
And that my friends,
Is the Russian Pinch.