Place them as a buff.
Scarecrow 100% useless regardless of build. Trap pulls all aggro and is destoyed very fast. Does almost no damage to mobs. PvP it's laughable... As Agi, yes, the other two are completely useless. As Str, TT and Demo are amazing skills actually. There was this thing you could do, throw down Timer Trap, Demo someone in trap range then pouch them. They still received ticks and would be defenseless against it. Not sure if it still works though. Haven't tried it in years. Demo also was not curable by detox.