From Worms Knowledge Base
Using this utility makes the worm who used it wear a dynamite belt, without ending its turn. The dynamite belt lasts forever, it should be clearly visible, but does not have any effect when the worm who wears it is alive. When the worm dies however, a large explosion is created, which deals the same amount of damage as a Dynamite.
This has many strategical uses. The most straightforward one is to use it to enhance kamikaze moves. It would make the Kamikaze weapon much more powerful, and if you have a worm with low health, you can always blow yourself up near an enemy, and then explode for extra damage. It would be also turn the worm who wears it into a significant threat in enclosed areas, and taking hostages with it would be extremely efficient, especially durring sudden death.
Obviously, it cannot be used on a worm who already has a dynamite belt equipped. It might also need to actually end turns when used, otherwise quick suicide moves might be considered really cheap since they require no anticipation. Have a worm with low health, equip dynamite belt, drop a dynamite on enemy worm, stay there, die, and you can easily deal up to 150 damage.