Well, the chemical reaction between the salt, water, baking soda, and aluminum makes the aluminum dissolve and if you leave it too long it punches holes. Doesn't harm the silver, it only pulls the gunk off of it. Just confirmed it works with aluminum foil as well.
I haven't attempted to clean my coins because I have preserved them well. The best way to keep your coins clean is to handle them with care and not to overuse them. However, I believe water and soap, traditionally, has worked very well. The ketchup method sounds interesting and I will have to try it.
You'd be surprised at how well it works. @paepleperson: Don't use it on any coins of value or any coins you want to retain an authentic/original look. It is very acidic and strips the coin of virtually ANY dirt/grime.
Well I always thought than when you clean collector coins it was decrease the value? Is this true? If it is true why are you cleaning them? Also that ketchup will surely damage the coins!??
Did i just read ketchup in this conversation (lol) I never heard of ketchup cleaning in my coins,, honestly, for a person who loves ketchup, i was wondering why I haven't tried it sooner? thanks for the post!