That is a very creative excuse but it cannot explain why this video which described the dangers of the practice and did not explain in detail how to go about do

That is a very creative excuse but it cannot explain why this video which described the dangers of the practice and did not explain in detail how to go about doing. It would be removed when none of the videos that demonstrate how to do this were taken down. I think a much more plausible explanation is that YouTube simply does not have an effective mechanism for deciding what videos to take down and which ones to leave up.