I also suggest you try cramming your snake into a 6qt tub for a week or 2 and then see if he eats... it's weird but has worked for me with snakes far larger than 500 grams!
I do have some small tubs that I can try this with if needed... who knows?
- Dave Harms - www.wax32.com | Pinstripe, Yellow Belly, Sulfur, Cinnamon ph G-Stripe, Pastel het Hypo | Pastel, Fire, Albino, Mojave, Lesser Platinum ph G-Stripe, Pastel ph G-Stripe, het G-Stripe, het Hypo, het Piebald, Pastel Yellowbelly