Can't help with the inside cleaning. I have a Q120, and from the start of use I have lined the inside with aluminum foil. After use, just remove the foil and toss it. Clean grill inside!! As for the grate, I remove it and spray it down with oven cleaner and let it sit for a time. Usually just a hose off and its clean. Sometimes a quick brush with a bronze brush is needed, but not often. Good Luck.
Wayne & Susan Biloxi,Ms
2012 GeorgeTown 351DS...2014 Ford Explorer/Brake Buddy