Yes the alcohol is a bit sooty when you burn it. And just like they said above - the 90% isopropanol can be hard to get. I think it's just because the 70% stuff is widely used for medicinal reasons.

Actually, I usually use these fuels with improvised stoves. For example, you can very easily build a stove out of an empty Coke can. Just punch a few holes around the base of the Coke can (about 4-5 holes, equally spaced) using a knife. Each hole should look like an indented triangle - you want good air flow into the base. The holes at the base should be about 1 inch (vertically) above the bottom of the can. Then punch a few open slots near the top rim. Then cut out the metal top of the can, leaving it open at the top.

Fill the Coke can with alcohol fuel up to the first row of holes, ignite it, and sit a metal coffee mug on top. Like i said above, your coffee mug needs to have a lid, or some condensing alcohol vapor can get into your coffee. This stove will heat the coffee (or water) inside to a fairly warm condition, but the fuel runs out. So you have to re-fill it and light it again to get it pretty hot. If you use a slightly larger can, should work much better. The Coke can does get pretty covered with soot.

Pete 2