There are always rumours about TikTok.
I’ve read articles where children have died from the so called black out challenge.
Holding your breath until you pass out is relatively harmless. You automatically breathe again once unconscious.
Wrapping something around your throat to stop you breathing for a challenge is a lot more dangerous because there’s a chance it won’t loosen to allow you to breathe again once unconscious.
There was loads of loads in fb about this challenge. Two (that I know of) deaths of children due to this challenge.
TikTok may say it’s not on their page, but once upon a time it may have been and then banned once flagged as dangerous