Not just lemon juice, but real lemon juice, in the green plastic bottles at Costco, I have turned the can up-side down with the holes on the bottom and placed a wieght on it to keep it under, check it at 12 hours with a small peice of green scratch pad , go over it lightly, if not good enough go another 8 hours and check it agin. always works for me. good luck. when your finished use a funnel and pour it back in the bottle,

[This message has been edited by Dwaine Buck (edited 10-07-2003).]