Mine was used for motor oil...no liner as the oil kept it from rusting...just burned it out, used a leaf blower to add some extra air to get it good and hot, then a quick spray with the pressure washer.
Link to my build if it helps...nothing to different but you can see the burn out process.
Golden Dome UDS "[URL=http://www.bbq-brethren.com/forum/showthread.php?t=149301]Dorthy[/URL]" | ~22" Char-broil "[COLOR="Green"]Char-lene[/COLOR]" | iGrill | Supersonic [COLOR="Blue"]Blue [/COLOR]Thermapen
Where there is love there is barbecue. – Gandhi