My suessful strategy with really loose players has been to tighten up and almost camp for great hands. Often these players are oblivious to what is going on around them and do not pick up on your tight play. You will get outdrawn by them at times, but in the long run you should be profitable. Additionally, I believe bluffing goes down in value because they often will not fold and you can not assume with a rags flop that they have nothing.