EDIT: I guess I should have looked ahead at the upcoming lectures, this was explained in lecture 155.
As a self-assigned challenge I decided to clean up the explosions, and I thought I would share it in case someone else found it helpful.
First I tried messing around with coroutines, but that was way too complicated. Eventually I checked the API and found you could add a timer to the Destroy() method, so I just made a script called SelfDestruct and added it to the death effect prefab. After that I just put:
Destroy(gameObject, 2f);
in the Start method of the class.
I would be curious to know if anyone else has a better or cleaner way of doing it, or maybe you just want to share your own ideas.
Thanks,
Matt