well, this grenade isn't much cheaper but its pretty darn good! the shell is made of rubber so if you hit someone it wont hurt them and it shoots >70 bb's at the same time in a 360* pattern with at least 15 to 20 ft radius! as for do it yourselfers, iv been spending the past week researching "cold smoke grenades" and unfortunatly they are still fairly new and noone seems to be talking about what materials they work on. best and cheapest way to go would be the standard formula you can find on youtube. hope this helps some