Expert: PAPAJACK - 6/28/2008

Question
Would heating a coin in water to kill bacteria  damage or take away from the value.

Answer
Hello George,                           

I have never tried anything like this.  
I am sure that boiling for a length of time would kill active bacteria but possibly not remove the debris left.
It may also discolor the coin especially copper ones since it will react with any ions present in the water.  
Excessive heating can also distort coins, warp them and you may even boil some contaminants into the surface.

I cannot say that boiling can give you the desired effect.
If you have low grade inexpensive coins try them first.

I will ask around and post more when I find out.
Thank You for the question and Good Luck

PapaJack