I have a question before I bust this rumor. Are you impling that Crunch will keep building up into an infinite amount of damage? If you answered yes, then I'm sorry to say that you're sadly mistaking. Let's go to the text. Crunch: DCC; Until the end of your next turn, if an attack damages the Defending Pokemon, that attack does 20 more damage. The bold part spells it all out. Okay, you Crunch once for 40. Next turn, you do 60. Do you do 80 next turn? Nope. Now if those words I have in bold weren't there, then it would get the desired effect. Since it doesn't work, use it against Rocket's Zappy(40 for Crunch and then it creams itself for 50-60 ouch!). You can also save Fire by doing Crunch-Flamethrower instead of two Flamethrowers in a row.