Water

Water is a chemical so rare even its existence is suspect on Cybertron, or at least so claims Ratbat. It cures Scraplets.

(Note: Assuming that Ratbat doesn't know about the underground river just outside of Primus's chamber (rather odd for an asteroid, come to think), he's still likely confused; as several humans later managed to exist without environmental protection gear on Cybertron without drying up like old corn. And that Ironhide had mentioned his 'water gun' right in the very first comics.

From Teletraan I: The Transformers Wiki, a Wikia wiki.