Sorry to burst your bubble Peaches, but no. Just no. Before i figured out betta care, that was what I was doing to Puffy. I don't have pictures to show you how well he was "thriving" (*coughdyingcough*) but I can tell you, it was bad enough for me to get really concerned about. Without any filter, cycling, or live plants, ammonia builds up so quickly, it's horrible. Even 100% daily doesn't cut it. When I was getting a tank together for Puffy and cycling it, and cleaning his death kit every day, he still had severe fin rot and biting issues and glass surfing issues. All in all, even with the best care in those things, a betta will become a wreck. Also, it's better to have clean water with a slightly stressed fish than dirty water and a dirty fish. Clean water combats sickness more than stress causes it.
Besides, the articles says the following:
The smaller jar (half gallon or so) may also be a suitable betta home but will require constant cleaning. bettas in this type of set-up will tend to deteriorate and more than likely will end up getting fin and tail rot and other bacterial diseases
Prometheus, I don't know if anyone has mentioned this, but you will want to invest in a good heater for your tank as well. Being tropical fish, bettas need constant warm water temperatures that do not fluctuate, otherwise they can become sick. :)