[Mauzen]

I use to use this:

pawn Код:

forward DestroyObjectPub(objectid);
public DestroyObjectPub(objectid)
{
    DestroyObject(objectid);
}

Then, when creating the particle object:

pawn Код:

SetTimerEx("DestroyObjectPub", time, 0, "i"; objectid_of_the_particle_object);

Where "time" is the estimated time the particle effect runs.
You could also combine this in a CreateTimedObject function that automatically creates and removes the object after a given time.