charlescarver:
Personally, I thought the setup above was fine. But I read about them and I felt like they would work well because the strike itself includes one, I'm assuming, but then I thought that since it included one it would be pointless for another.
I think the striker has a solenoid (electro-magnetic actuator) rather than a relay (solenoid activated electrical switch).
I think a relay would be superfluous. You would typically use a relay (instead of a transistor) if you needed to control AC voltages.