Reddit reviews Hashish

"Smoke is often exhaled before most of the THC from the smoke in the lungs can be absorbed by the bloodstream. The smoker might not hold the hit for 20 to 30 seconds, exhaling too soon or coughing. Smokers rarely absorb a majority of the THC that is in a toke"

-Robert Conell Clarke, "Hashish". Pg. 270 under the heading "Smoking Efficiency"

People are weary about having smoke in their lungs for a long period of time due to the byproducts of burning plant matter and resins. The science still doesn't make people totally comfortable with it, especially with the hysteria centered around the tobacco - lung cancer links.

Don't take anyone's word for it. Not mine. Not Clarke's.

Do a test for yourself:

Fast from Ganja for a week to clear your head. Wake up and have a good healthy breakfast. Get baked. Smoke a fixed amount in one sitting (however much you like to smoke in a sitting), holding in your tokes for 5 seconds before exhaling. Note the effects. Be sure to save that amount of the same herb for the second part of the experiment.

Fast from Ganja for a week. Wake up and have the same healthy breakfast. Smoke that same fixed amount of the same strain, holding for >20 seconds. Note the effects.

Be sure you do the same things in both sessions. Eat the same foods. Smoke the same strain. Use the same apparatus to smoke from. Your high is greatly influenced by your overall well being, mentally and physically. If you put some nasty ass food in your stomach and then smoke, you can often trigger a not-so-pleasant high.

IME with this experiment the longer I held the hit, the higher i got.

There are also a lot of other ways to get more out of a toke if you're freaked out about lung damage:

PROTIP: Exhaling through the nose is a fantastic way to incorporate the olfactory bulb into the equation. This will also give you different effects and can often induce a lot of non-cannabinoid related, positive psychological effects.

TIPTWO: Don't torch the fuck out of your bowl. Heat destroys THC. Corner it lightly. A light, airy, lungful of smoke will go much farther than a thick, milky, dense hit will. The latter will give you more of an effect due to lack of oxygen than it will from the THC. The lower the temperature that you can heat the herb at, the more effectively you will transfer the THC without destroying it.