As a matter of fact I often weigh my hits with a triple 0 scale. I only smoke rocks that I cook myself so I have a pretty tight grip on quality and potency. I cant imagine how big a rock would have to be to cause cardiac arrest. I cant hold that much for sure. My lungs will not accept anymore vapor than what is produced by about 35 to 40 mgs of purified freebase. Not all the excess oil runs inside the stem. As a matter of fact, if you are efficient with temperature control and you prepare a proper chore, none of it will run inside the glass. You can put 50 mgs on there if you want, but you wont get the vapor of 50 mgs. There are certainly plenty of people shooting shots that are larger then any crack dose without trouble.
With all that in mind, the safest course of action is not to pick up the habit. Once the decision has been made to pick it up, the best harm reduction behavior you can engage in is to cook your own to manage quality and content.
I dont get these sweats and agonizing effects that many people have mentioned. I don't feel comedowns. I get bellringers that last 10 to 15 minutes, that dont make me feel like I am chasing a lost feeling, and that leave me satisfied enough to put it down till the next time. Basically its just another ROA for one of the most commonly used stimulants in the world. It gets a bad rap from the media because of the section of the population towards whom it is mostly marketed. Crack dosnt create desperate criminals. It is predominantly only sold to desperate criminals. They are the only people who have money set aside for it each and every day.