I have seen it used. Worthless.

I believe the "technology" comes from the 60's/70's where people used to burn that inside to cover the Marijuana smell. (idiots!)

If you can get it lit in the field, you have to pray that there is not much of a breeze. If there is a steady breeze, it only makes the incense burn out faster. Longest I have seen it burn is 2 minutes. Then what do you do?