You can get black "snow fence" rather than orange, and that will save some effort. Also plastic-coated fence will work, but a bit more pricey.

Also when planting lilies, they are big nutrition lovers. Rather than hoping there is enough natural stuff on the bottom, initially plant them in a biodegradable peat container with fertilizer, stones on the bottom of the container, and rich water-saturated soil so it doesn't float. You can also purchase specialized fertilizer that you need to make sure is trapped in the soil of your container.

Then try to excavate a bit (by hand) to set the plant into the hole, then spike the whole works down. Put fence over the top to protect it from animals. Eventually the bucket will rot out, and the roots and rhizomes will find their way across the bottom.