Ooohhhh, gross. I'm sorry, I would no longer be tactfull. I'd be saying on a daily/weekly basis "coworker there is a strong odor coming from your office. Would you get rid of it." And I'd be encouraging my other co-workers to do the same.
I had an office along a short hallway with 6 offices. The hallway doors were required to stay closed and company policy was to keep your door open unless in a private meeting. One co-worker changed his diet which created a lot of flactulence. We were all long term coworkers so probably little more open with each other. I had no problem going to his open door spraying air fresher and another co worker eventfully hung on the wall by his office door one of those airfreshners that release a scent periodically or you can tap a button. After a month we were still ready to kick him off the hall until his wife threatened to kick him out of the house if he didnt switch his diet.
I think what you and coworkers did was rude. Air spray over fart smells makes the smell worse and just covers it up. Some of those scents are really powerful and give people headaches. At least his farts are 'natural'. Why was your smell covering better than his original smells?
Farts might be "natural," but I'll take an overpowering fake scent over a fart smell any day.
I'll second this......seriously, VorGuy could be a weapon of mass destruction if you feed him certain foods in any quantity (I hesitated over whether to use the term "right foods" or "wrong foods" here).
But there are foods that have skunks holding their noses and fleeing the scene (butyl mercaptin, if I recall correctly, is a major component, for those not familiar with the North American continent's master of the weapon of stink - it can be smelled for miles under certain weather conditions and will render any animal so doused unable to use its nose and possibly it's eyes, depending on the marksmanship of the particular skunk*).
*At least until the oily liquid can be rubbed off with earth or neutralized chemically by humans (vinegar, tomato juice, & several de-skunking commercial applications).