Update: I have fiddled around with my home made artificial star for a while but have never got it particularly bright at distance. Usable, but....
Then I saw this commercially available version. the Hubble Optics 5-Star artificial star:-
http://www.hubble-optics.com/artificial-stars.html
http://www.hubbleoptics.com/files/Hubble5starFAQ.pdf
Reasonable price - USD 24.95 shipped
Tried it last night for collimating my old C8.
Found a darkish location - in tree shadow from some security lights. I set up my home made on a tripod about 50m from the scope. The Hubble 5-star I balanced beside the home made and pointed it at the scope.
Quickly determined I could see the 5-star much better so went with that. I chose the middle hole (perhaps the "Goldilocks" hole - not too bright and not too dull!) and used the supplied magnetic blank to cover all holes but that one.
After that it was easy to observe the diffraction rings and tweak the SCT collimation to a much improved condition.
Looks like a worthwhile accessory.