Is exhaling smoke wasteful?

[_DankOpiAmp_]

I think most of the stuff you exhale from smoking something is mostly waste products or substances the lungs can't pick up. I don't think holding your breath for most drugs will vary the milage (altho nitrous, dmt and saliva are a bit different when it comes to holding the smoke in).

Salvia is burned so why would it be different? The only real difference is YOU notice the difference more readily when you hold it in. If you hold smoke in long enough nothing will come out when you exhale so there isn't shit that won't absorb. The only waste product is carbon dioxide.