Chosen Solution
What do I use to clean the inside of an iPhone 5?
Disconnect your battery and your display. Use 99% IPA to clean and a plastic brush (toothbrush is fine) to scrub. Don’t be shy with the IPA, it will evaporate fast. I won’t use anything other than 99% on boards, the risk of doing damage is just too high. I am curious why you need to clean your board though. Have a little spill? :)
Try using a lint free microfiber cleaning cloth and qtips to remove dust and other stuff inside. If you can get 92%+ alcohol, a small hobby/paint brush, jewelers loupe (20x) and an anti-static cloth that will probably way more effective. Use the brush to gently brush on the alcohol, use the cloth to blot away any debris, and use your loupe to check where you cleaned. Don’t scrub, just smoothly wipe the brush in a small section and blot. Just remember POWER OFF YOUR PHONE. (And eventually, remove your battery).
