Cleaning internals can be a simple task and a nice earner, when it comes to homes most women try to clean the insides with traditional type glass and mirror cleaners which is a disaster as all they do is leave behind streaks and smears, its a fact one of the worst products used for cleaning glass and mirror surfaces are traditional type glass and mirror cleaners as they contain IPA,ammonia,solvents,etc, and its these ingredients that end up leaving behind all the greasy residues, a good solution to this problem is first use a magic eraser pad damp with water to break down all the greasy residues, then use a damp microfiber cloth to remove all the loosened residues, then use a dry microfiber cloth to polish off for a streak free finish, this method is far more effective than using an applicator and squeegee and will leave a superior finish, anyway just some different thoughts on cleaning internals, why not try it you might be surprised.