Monks Making Smoke

I recently received the latest Abbey Newsletter from St. Gregory's Abbey. Among the various spiritual offerings in this issue was the following photo from their Fourth of July activites:

Now, good Prior, what some of us would like to know is what was the exact mixture that you were smoking that caused such a marvelous cloud? And, is such smoke making a spiritual discipline that you would recommend?

Inquiring minds want to know.

J.