Had a smoke system on my Pitts Special S1-T and my Glasair III. They were necessary for airshow work but as mentioned above, what a mess. In my Glasair I was pumping 1 gallon a minute into my exhaust and the smoke was awesome. But if I didn’t have every belly and tail seam taped up the cockpit filled with smoke instantly too! I can’t remember how much Corvus oil cost back then because the airshow always provided it. But let’s say it’s $10 a gallon today. That’s $150 to make smoke for 15 minutes. Then as soon as you land your plane is an oily mess. So no, it’s not fun, and it’s not cheap either. All the best.