More Winter Insects--Burlese Funnel

What is a Burlese Funnel? According to the book we have been using it is an insect strainer to examine insects who may be wintering in the soil. ". . . an effective tool for capturing insects that live in the soil, or decaying leaves."

Picture from book:

The one we made:
I didn't want to use my kitchen funnel so I cut off the top of a soda bottle. I also didn't have any wire mesh on hand (add to shopping list, right? maybe not) so I used a double layer of cheesecloth held into place with one of my girls' hair elastics. The book suggests to use rubbing alcohol in the jar, but then says "If you do not want to kill the insects, use water instead of the alcohol." Which I think is a pretty silly thing to say because our lone insect drowned very well in the water.

How it works: Put soil into the funnel, place light above funnel and leave on for 6 hours. "The insects in the soil will move down the funnel away from the heat toward moisture and tumble into the alcohol."

Our results: Yes, you read correctly above, we only managed to have one insect tumble out of our funnel. Our insect was about half a centimeter long, and millipedie-ish, earwig-ish looking due to the many legs. As I mentioned he drowned in the water and when we tried pulling him out to examine him further, his body fell apart. Apparently he shoudln't have been left in the water sooo long. The books suggests "If you don't find any insects, try again with soil from another place. Beneath a tree is a good place to find soil containing insects." We have been trying soil from 4 different areas of our yard all week long, and no luck.
Hypothesis of why it didn't work: No bugs in the ground (obviously), but why? Not fertile enough to attract bugs, too wet, the weather warmed up so all insects wintering came out, though they probably regretted it with the snow today.

I think we will try again, but I plan on collecting some soil samples from our nature walk this weekend to use. So I'll update when/if we have better results.