He is only copying the as advertised video showing that the charge is not harmful and as you see he wasn't. But ya I'm not doing that.
As far as detonation the manufacturer states
.Will the ball activate if in contact with heat?
No, the ball can withstand heat of up to 200 degrees and will not activate. The ball self-activates only when in contact with open flames
Says must contact open flame it is just fire works fuse to ignite it, but high heat may effect product. Would be interesting to see someone put it in a controlled heat oven to see what happens and if just heat will ignite fuse.
So I ordered a few of them from two different makes in three different sizes. I will be the group guinea pig and yes I will be putting one in the engine compartment so hope to never update this but will see. Most of them just for around the house mainly in the garage.