hso, I did, If you note the title of that portion of the artical I posted it's entitled "Health Effects". MEK is present in many paints and solvents, even in cigeratte smoke, ect., ect. I did read the link about MEK that you posted and. Overall it tests as a much less deadly chemical compound than Lead which is an element which we're all exposed to as shooters.
Actually it seams to be one of the many chemicals one needs to use with care but not to be overlay afraid of which is the case with loads of chemicals we use from the gas and oils in our garages to the chemicals under our kitchen sinks.
For an on topic note, I'd just use one of the many copper or lead removing chemicals available on the market rather than try to mix up my own, other than the tried and true Ed's Red. And I still advocate the use of Mobil I as a lube and rust protectant for firearms used regularly, thats not for a long term storage tho.