Your problem with the roach acid blast not happening is because you changed the effect. The Action actor for the roach's attack activates when the original effect of the weapon activates and since you changed the effect it stopped working. All you have to do is change the actor so that it runs when your DoT effect activates.
Your problem with the roach acid blast not happening is because you changed the effect. The Action actor for the roach's attack activates when the original effect of the weapon activates and since you changed the effect it stopped working. All you have to do is change the actor so that it runs when your DoT effect activates.