I like the technique a lot. Having a tarp or poncho to put the dirt on is a key factor. I use a tarp for dirt when ever I’m digging in landscaped areas to control the appearance of the ground. You can put a lot of dirt on one and not leave a trace of your activity.
Using a tarp would allow you to dig a Dakota Fire Hole and not leave evidence.
http://survivaltopics.com/the-dakota-fire-hole/ A much more involved fire, but useful to hide a fire.