I wouldn't recommend dipping the coin unless it's just a bullion coin - any dip that can clear toning will forever damage the top layer of the coin resulting in a dulled coin that will be significantly devalued and very difficult to sell.
The only way some dealers manage to sell dipped coins for high prices is by not declaring that the coin has been dipped then attacking and discrediting third party grading so their buyers won't verify the originality of their coins.