I wouldn't use Simple Green on Hypalon. Most inflatable boat cleaners have toluene as the 'power' ingredient - it's the same solvent you'd use to prep it for repairs. It will harm you more than the fabric, so take due notice thereof and govern yourself accordingly. Follow it up with a couple applications of 303 - NEVER, EVER use Armor-All on an inflatable. It will dull out worse than it was when it wears off, WILL damage the Hypalon in the long term, and will prevent ANY future repairs from ever bonding properly.
Armor-All is bad, bad news for Hypalon.