Few years ago I remember getting a call from a customer who needed a key made for his 87 Ford Mustang GT. The customer had the vehicle under cover for many years and at some point lost track of the keys to it. I was at the beginning of my way at that time for originating automotive keys, but I figured I should be able to handle it. I had to look up the best way to make a key for this type of Ford vehicle and it seemed that impressioning was the best way I could do it.
Once I got to the customer's home, I took the time to examine the condition of the locks on the vehicle which were not great. I had a feeling that originating a key for that vehicle would not be a "walk in the park", but I still had the interest of trying to make a key for it. As I was following the impressioning procedure carefully, I noticed I could not get a clear look at the cuts, so I could make the key. The only way that came to mind that would help clean the lock a little bit was using WD-40. However, the lock was so contaminated from the inside that it didn't help.
I decided to give a call to a Boise locksmith co worker of mine who has been in the business much longer than I have and probably ran into this type of issue before. Fortunately, he came across old model Fords with dirty locks in his time where he needed to come up with a decent way of cleaning for the sake of impressioning. Turns out that pipe cleaner was the best way to go in that particular situation. After a quick run to the hardware store to get some pipe cleaner, I was back and ready to make another attempt impressioning the lock, but not before soaking the lock with the pipe cleaner for few minutes. After a short wait, the lock was as good as new to my surprise and I was finally able to make a key without any further issues.