What's With The Worm Trench?

I have read of a few people who simply dig a small trench and add some food and some worms and that's it. That isn't too hard, is it? I have begun mine. It is not doing much right now. The reason I dug the trench was because of a natural disaster. The disaster was caused by strong winds and a poorly thought out compost heap.

I had wired 4 wooden pallets together and added some yard and kitchen waste. I added a few leaves and some chicken manure. Then, the best part was adding the palm leaves. I added them by weaving them into the pallets. When the winds came the leaves were tall enough to cause the whole thing to fall over. I didn't want to have a big heap in the yard anymore anyway (although I am thinking that a proper compost heap may help out our recycling efforts). So, I dug a trench and stuffed the contents of the heap into it. Most of the heap was composed of cardboard and other carbon sources.

Now I want to get the pile a bit more active. I have been wetting the pile down every morning but it still seems to be taking a long time to break down. I am going to add more chicken manure and possibly some horse manure to the pile. I know the horse manure will be good for the worms but the chicken manure may be a bit too hot. I don't have enough to fill the whole trench anyway so a little at a time shouldn't hurt. I am excited to see the effects of a worm trench next to the garden.