Haven't used the device so can't vouch for its effectiveness.
Claims:
1. Produces up to 17%* MORE HEAT from your Fire
2. Dramatically REDUCES SMOKE emissions by up to 50%*
3. CLEANS the chimney while the fire burns
4. CLEANS the heater glass window
5. EFFECTIVE for up to 3 months* of continuous use
6. Contains NATURAL Ingredients
7. MULTI AWARD winning Invention
In independent tests carried out by the Australian Home Heating Association (AHHA) testing laboratory, Smartburn reduced particulate emissions by 37 percent on average, (ranging from 24 percent to 50 percent depending on the intensity of the fire). The tests also revealed particulate emissions are reduced by an estimated 2.2kg for every tonne of wood burnt or 11kg over a three-month period.
Source: http://www.abc.net.au/tv/newinventors/txt/s1400040.htm
I'm skeptical. Catalysts to aid in burning are usually a honeycomb structure that air passes through. I wouldn't say that its definitely bullshit, and I'd certainly give it a try
As it stands I currently have a slow combustion. Apparently these don't work as well in the slow combustion.
We use SmartBurn, and have had mixed results. First time we used it, there was a very noticeable difference. The second and third time, there was no change, and we still had a lot of smoke which choked out the flames. Apparently you need to keep it level in the fireplace, as it has a substance inside which turns to liquid when heated, then gas, and that clears the soot. If it's tipped, the liquid can tip out and be ineffective.
We also found we had to climb onto our roof and clear the top of the chimney - which was super crusted. That helped a lot.
I'd recommend it, but it's definitely not a cure-all.
They absolutely do work.
The average person with a wood heater has no idea how to use it responsibly and the problem is it's their neighbours that pay the price for their ignorance. Apart from when you first start the fire, if you have visible smoke coming out of your flue you're doing something wrong or there's something wrong with the heater.
This idea that it's every mans (it usually is men with this attitude) right to burn wood in whatever dirty manner they want should be cracked down on by councils - it may have been ok back in the neanderthal era, but living so close together as we do it's extremely damaging to peoples health. Parts of Tasmania are permanently blanketed in thick smoke for nearly six months or more a year.
If you have aa wood heater and live less than 500 metres from other people you have a responsibility to at least try Smartburn.
I have a neighbour that aggressively poo-pooed Smartburn, then after years of smoke from him (and a permanent lung condition for me) I got him to try it and what do you know? No more smoke.
Snake oil?