My son and I just returned from a quick overnight trip up Mt. Greylock in western Massachusetts. We stayed at the Peck's Brook Shelter and when preparing our evening meal, the beans burned slightly when heating them in a SnowPeak 700 over the open fire. I've scrubbed the titanium with an abrasive sponge and an SOS pad. It hasn't made a dent in the stain/burned bean deposit. Any ideas on how to best clean it. I'm reluctant to use course sand paper because I figure the scratches might just encourage and attract more food deposits in the future. Thanks.