Corrostop

Invented by Perceptor for the purpose of removing and preventing corrosion of any form, it is best known for being the only known cure for Cosmic Rust.

Unfortunately, after the initial batch was exhausted protecting the Statue of Liberty and curing Megatron, it was discovered that the supply of the key ingredient, Ingredient X, had been completely used up and could no longer be found anywhere. Fortunately, after Megatron attempted to spread the Cosmic Rust amongst the Autobots, they were still able to use a matter duplicator to create a large enough supply from scrapings off the Statue of Liberty to cure everyone who was infected.

It's unknown whether a new supply of Ingredient X was ever found, or if the Autobots continued using corrostop for any purpose afterwards.