Well, you can always try adopting the rules we used in a Style BnG tourney in the olympics:
1) if you hit your opponent with a zook, you must hit your opponent with a grenade before you can use the bazooka again
2) for the grenades, there are 3 possible shots: normal grenade (A), lg grenade (B), grenade that's been bounced against the floor before flying off (C) (i.e. aiming down) with or without lg (though usually with lg)
If you hit your opponent with shot A, you're not allowed to attempt to do so again until you've hit him/her with shot B and C. Same applies with the other shots of course
Considering there's only a limited amount of teleports, this makes it very unwise to place your worm on the edge of the map or within a space that's too well covered by the map.
Give it a thought