Dipping a coin can often make marks much easier to see. That's because heavy toning and dirt/grime will often cover up marks thus giving the appearance that the coin is a higher grade than it really is. This is where a lot of people make a mistake by dipping a coin when not realizing this. And that is why many of them will then try to re-tone/re-color a coin in order to cover up their mistake. However, there are a great many techniques that coin doctors can use to cover up marks - dipping is not one of them.
Got to really, really agree with GDJMSP on that one. A dealer I know showed me 1916D Mercury Dime he thought he could improve with just a little dip in Acetone. Not a cleaning, just a brief dip. Unfortunately there was plain old dirt in some really not noticable scratches prior to the dip. That Acetone removed that dirt and wow, nice scratches.
OK, how about zapping? If anyone recalls, I have that Panama 20 Balboa of the conquistador which I really like, but some abrasions in the field really bother me. I don't want to ever sell it (in fact if silver goes down, watch out, I'll start hoarding them). PM me recommendations if you feel it necessary to limit the viewership.
You want my opinion - just buy another one that you like better. They aren't hard to find. It's much easier than trying to doctor (fix) the coin you have.
You know there are so many people that will spend thousands of dollars to make a hundred dollar item look better. Not sure of the value of the coin you mentioned but if you plan on spending a lot of money and time to improve it, I just can't see the purpose. People do it though. An example is all the people that send in or go to coin stores and purchase all those coin cleaning items. Then the coin is now worth less and they paid to improve it for nothing.
I would strongly advise not to try that unless you are trying to clean a badly corroded coin. You put that silver Balboa in there and you'll end up with a mess.