There is no way you can clean a coin without devaluing it.
You refer to specifically to a 1930 Penny, one of the potentially most valuable Australian Coins ever issued into circulation.
To get mud off, and only if you absolutely insist on risking your coin, you can use very mild soapy water on a copper coin, and pat it dry (do not rub) very carefully with an uncoloured and unbleached paper towel.
how much is 1938 penny worth
The value of the 1938 wheat penny varies by condition. This wheat penny can be worth 35 cents to 12 dollars.
Penny Pitou was born in 1938.
A Penny..the other day I found a penny from the 20s. Its still a penny not much as changed.
Penny Paradise was created on 1938-09-24.
.10
Penny Morrell was born on February 4, 1938, in England, UK.
A 1938 penny may be worth several dollars, depending on the condition of the penny. A penny in poor condition may only be worth one cent, but collectors are often willing to pay more for one that is in excellent shape.
A Clean Sweep - 1938 is rated/received certificates of: USA:Approved (PCA #4947)
A 1938 Lincoln Cent in good (G-4) condition carries a value of: 5 cents.
I think mostly copper.
Prison Without Bars - 1938 is rated/received certificates of: UK:A