Birchy and Boatman had a minor spat a couple of months ago in these columns, concluding in Boatman asking Birchy what 'oil' was for in rhyming slang. I'm still waiting for an answer. What is oil in this context?
"Oil" doesn't seem to mean anything in rhyming slang; the nearest phrase seems to be "oily rag" for fag (ie cigarette). Nor does there seem to be anything fitting the context in other types of slang. Perhaps Birchy meant to type "oik" when he posted "what an oil I am". "L" and "K" are of course next to each other on the keyboard.