yield WaitForSeconds problem?

When I add the command "yield WaitForSeconds(3) the next line of code is ignored “Destroy(gameObject.FindWithTag(“Particles”));”
If I remove the “yield” command the “Destroy” command works fine however I need the delay. Does anybody know what I’m doing wrong? I think this is a brain fart. I just can’t smell it. Thanx

#pragma strict

function OnTriggerEnter (myTrigger : Collider) {
   if(myTrigger.gameObject.name == "ExplosivePrefab(Clone)"){
   yield WaitForSeconds (3);
   Destroy(gameObject.FindWithTag("Particles"));
   
  }

}

You could use the timer from the Destroy function

function OnTriggerEnter (myTrigger : Collider) {
   if(myTrigger.gameObject.name == "ExplosivePrefab(Clone)"){
      Destroy(gameObject.FindWithTag("Particles"),3.0f);
  }  
}

The second parameter is a timer in second.