Traps only have 1 "charge" -- just use your Summoning Doll as a bomb-sniffer. When he gets blown up, wait until the respawn penalty cools down, then shuffle another one off to die.
If you have > 200 hitpoints on one of your characters, 1 trap won't kill it, and after that, you can just run your poor skeleton buddy down the hall a ways to see if there are more traps (there always seems to be more than one).
