Hi, Meucci. Welcome to TNet.
Your question is the ubiquitous can-o'-worms in any forum. Everyone has an opinion. When challenged, no one can come up with a bona fide process by which the coin grading companies use to clean and preserve coins. Its like its some huge secret. All we can tell you is that there are many different ways to clean and preserve coins at home, and the only advice that I can give you is to NOT clean anything until you've studied up on this.