If you're not in a big hurry to CTB, in the not too distance future, I'll be conducting a series of "test runs" using a tent and charcoal to determine the amount of charcoal necessary to produce a level of CO in the tent at, or above, 10000 PPM (parts per million, which is the concentration one would want in order to have a quick and painless death. I'm going to be purchasing a meter ($400), and what I'll do is determine the exact amount of charcoal in number of briquets, along with the best brand. I'll report my findings along with pictures of the charcoal I used, the type of buckets and size I used, the chimney starters I used, the brand of charcoal I used, pictures of the meter showing the level I was able to generate, and I will summarize it all by reporting the amount of charcoal used in number of briquets needed. So, if I determine three 1.5L buckets are needed, and in each bucket 25 charcoal briquets are necessary in order to produce a level of 10000 PPM, that's how I'll state the findings. Once I determine the amount of charcoal needed, I'll repeat the procedure at least 3 times in order to make sure the procedure can be duplicated. That way others who follow me in using the CO method won't have to buy a meter, which I know is out of the reach of many. Doing it by number of briquets will very much simplify the procedure and eliminate the possibility of someone severely injuring themselves by not generating enough CO.