Run away fast.  That stuff is nasty.  I use flaked carnauba wax per a recommendation from Walt Melander of NEI fame.  Available on eBay or Amazon among other places.  I light it after sprinkling some on the melt and let it burn.  If I am lucky, I will have remembered to take down the paired smoke detector that goes off in the garage as well as the shop where I am casting in front of an open door with a fan blowing out.  If I forget about the detector, the family comes running after the one in the attached garage goes off. 

(You need to Login or Register to view media files and links)

   I have been using Marvelux for ten years or so and have no problems with it. It works well and produces little smoke which is important to me. I used to use a bit of beeswax but the smoke made it impossible to flux inside without opening windows and using fans, not too practical in cold weather.

Marvelux flux rusted me pot. I use old bullet lube. I use a striker to set it on far which burns up the smoke. I never cast bullets in the house. Don't think the fumes er good fer ya.

I've been using it for many years too.  I can't compare it to anything else because I haven't really tried anything else.  My Lee pots have a little surface rust on the top but they've been in service a long time.  

Maybe I'll give those flakes a try and see how it compares.

Chris.

Nothing but old candles for the last 70 years of casting. Ignite the smoke.
Tried Marvelux flux. the parrafin candles work better
to re alloy the dross tin back into the alloy.
beltfed/arnie

Smoke,
I have an opinion on this that you can ponder... 
In the past I have had access to, and used a lot of range lead, several tons of it anyway.  I do prefer using Marvelux for the melt that is really dirty, but don't use your regular lead pot...
I use a cast iron pot on a cheap propane burner out in the middle of the yard.  Melt all that dirty stuff, flux heavily, pour into ingots, Then use wax to make your mix with tin - in another pot if needed.  I found a cheap cast iron pot made in the far east,  I stamped "used for lead - not for food" in the bottom of it.  Just be careful not to load it heavier than you can handle, ask me how I know that...
GT