There are a few great discussions on controlling the lily beetle in the Far North Gardening forum,

http://forums.gardenweb.com/discussions/1881727/red-lily-beetle?n=21 

and

http://forums.gardenweb.com/discussions/3943013/oh-no-the-lily-beetles-are-here?n=11

Yes, it looks like from reading above frequent applications of neem oil does work.

For me, I check frequently and tap the red beetles into a container of soapy water. If I see larve, I cut the leaf and drop it into the water. However I do not have quite as many lilies, so it is manageable, although it does require work. Unfortunately it seems most environmentally safe methods seem to require more work than chemicals.

I did read they are testing out introducing wasps to help control the beetle, http://globalnews.ca/news/2874158/tiny-asian-wasps-brought-in-to-fight-calgarys-invasive-lily-beetle/ 

Good luck & I encourage you to share your progress with us in the Far North forum.