i usually use them in a metal pipe...

but in a glass pipse, i prefer not to...just take in the smoke gently...many screens get all nasty, and then you have to suck harder like a whore trying to get a damn hit...

if your smoking shake, or ground up bud etc...use a screen...

my pot is usually just barely cleaned, just taken the big stems and beaners out...then i maybe break a nugget in half or something, and toss er in...