We bought a pair of food grade drums from a guy in Kaneohe last year. All we did was drill our intake/outake holes, Pam'd the inside heavily and did a high heat burn with a 20 lb bag of Kingsford. Worked perfectly for burning of the interior.
A few days later we hit it with high temp green and black paint from City Mill.
No complaints yet and the UDS is my wife's favorite smoker.....hands down over the Pro Qs, WSMs and offsets.
Hope that helps.
Crash - HIBarbeque.com