Flash Bombs are crafted by engineers, but they can be used by anyone. These are an excellent item to market to all levels of PvP players, especially twinks. Why are they so good? They are usable by all players, not just engineers. They share a cooldown with other bombs, which won't be an issue with non-engineers. Anyone can toss these in a battleground and using one of these can easily save the day in Warsong Gulch. They do have a chance at failure when used on targets over level 60. The big thing with these is you aren't restricted to npc beasts. You can use these to "fear bomb" hunter pets, druids in cat or bear form, shamans in ghost wolf, and also enhancement shaman spirit wolves. Thus making these very effective for twinks to fear flag carriers in WSG. Unlike most fears, damage does not interrupt their effect so you get 10 seconds of free beatdown!
How To Get The Pattern?
The schematic is a quest reward from the follow-up quest Flash Bomb Recipe offered after completing the quest Pearl Diving by Rigglefuzz in the badlands. This follow-up quest that rewards the schematic is only available to engineers. Do yourself a favor and farm the 9 required Blue Pearls for the quest before you go get it. You can save time and turn it in immediately instead of flying back to Stranglethorn Veil to hunt the Blue Pearls found in the Giant Clams around the sunken city occupied by murlocs outside of Grom'Gol Base Camp.
Learn It Or Sell The Pattern?
The Gnomish Coin did a post earlier this week about getting this pattern to sell for 300-500g. I am saying learn it yourself and sell these flash bombs to PvP players. Definately market these to the twinks on your server. Only an engineer can do the quest for the pattern, but crafting these only requires 185 Engineering skill. The Blue Pearls are easy to farm with a druid in aquatic form, especialy with the glyph to increase swim speed. Other classes can bring a waterbreathing item or potion or the trinket from winning the Booty Bay fishing derby. Keep the blue pearls in your snatch list and buy up any that players dump on the auction house for cheap.