Large Cast iron Cauldron
Smaller cast iron Cauldron or pan that will fit inside the large one
Epsom Salt
Rubbing Alcohol
Fill the small Cauldron or pan 3/4 full with Epsom Salt .
Pour Rubbing Alcohol over the Epsom Salt until full to the rim.

This is recomended for outside use only. After invoking the quarters and blessings, light the cauldron by dropping in a match. Normally I don't like matches in rituals but in this case a lighter or candle flame can be very dangerous to use. This will burn about 3 hours or more and produces no smoke which may attract the wrong attention.

Given enough time the flame will burn out, if you need it out sooner put a lid on the large cauldron and the lack of oxygen will make it go out. Remeber that the inside Cauldron or pot will be extremely hot and allow it to cool before attempting to move it.