I thought some people wold be interested to know a very decent natural bore cleaner can be made from eucalyptus oil and pure tupentine,or mineral if your not into natural, cheaper too) 2/3 oil,1/3 turps. Eucalyptus is a very strong cleaning agent as most aussies know and is exceptional at cleaning stainless. An old hand told me this and i tried it, works very well, removed all carbon and crud. Im not sure how it removes copper, but for how gentle it is certainley cleans well. I recomend scrubing it with a soft nylon brush and leaving for 15 mins then patching>
