I just put the regular cheap in the brown plasic bottle 3% peroxide undiluted in a old coffee cup about 1/2" deep and microwave till it is boiling and then carefully slide up to 3 coins into hot bath and watch them bubble.It removes that extreme tuff coating as well as light soil from the coins after a few min.I like to check them after 3 or 4 min. to see how they are doing and rub them a bit with a very soft micro fibre cloth.If still have some crud on them repeat over and check.When they are mostly cleen you can use a Qtip and a wooden tooth pick to get into the detailed areas.Just dont over do it or the nice dark green patina can fade and the coins will turn a strange color some times.
Any one else using this method feel free to chime in as I am no expert by any means,Ray.
PS. Best to practice on a more common coins untill you get your method perfected
Another thing I have found is to not use water at all on Indians and early wheats for best results...
One more thing,after cleaned I like to put a drop of pure olive oil on them and wipe with a soft dry cloth as a means preservation..
Any one else using this method feel free to chime in as I am no expert by any means,Ray.
PS. Best to practice on a more common coins untill you get your method perfected

Another thing I have found is to not use water at all on Indians and early wheats for best results...
One more thing,after cleaned I like to put a drop of pure olive oil on them and wipe with a soft dry cloth as a means preservation..