Thanks for the reply, no ideas man. Personally, I haven't lost any bulbs due to drainage because I am continually amending the soil each spring, but your method is certainly a good one. I think your method would also protect bulbs from our grey squirrels who love to dig up tulips, especially.
What is really interesting to me about Lloyd's book is that he is actuallly growing the lilies under water. He doesn't say whether or not he lifts them at the end of the seaon. I guess I could buy some cheap bulbs and give it a go.