[Adder]

How effective can the bombs actually be if they first have to penetrate clothing and flesh?

Seems their effect would be dangerous only to the carrier. [I am thinking of those stories of brave guys who jumped on grenades for example.]

[Issaquahking]

Top surgeons have confirmed the feasibility of the explosive implants. Explosive experts allegedly told MI5 that a sachet containing as little as five ounces of PETN could blow "a considerable hole" in an airline's skin, causing it to crash.

With a little explosives training, you learn how to adjust what you need, to get the job done.