OK, I know this might sound weird, but I have used Brasso to clean scratches and scuffs off perspex/plexi windows. Apply the Brasso in sections using just your index finger. Create a wet slurry and rub in the direction of the scratches until it begins to dry. Then add some more brasso and apply with the finger again. After doing a section, gently wash off the Brasso with a damp sponge...do this a number of times. The area looks foggy but can now be buffed clean with a microfibre cloth (the kind used for eyeglasses, etc.). If a scuff or scratch persists, work on that area again. I have been successful with everything from eyeglasses to the cover on my B&O stereo. But be careful and use this at your own risk!

In addition to tape (or instead of it) I once used a small, thin shim of polyethylene plastic (cut from a blister package) to hold a flat cable in place. Cut the shim to just under the width of the connector and about twice as long. First insert the cable and slide the shim on top into the connector as tightly as you can. (This is assuming the connection points of the cable are down toward the pcboard, of course.) In most cases there is a bit of space above the cable that the shim can wedge into. It doesn't hurt to try this as it makes a better physical connection than tape.

In the case of digital cameras, remove the battery asap. Otherwise the flash charging circuit could short out sending high voltage across the motherboard. Then use one of the appropriate iFixit procedures to remove the back cover of the camera. Let it air dry, for a week before touching it. Reassemble and hope for the best.

I wouldn't recommend Acetone as it is a solvent for plastics and could do serious damage to case parts. However, in addition to Isopropyl (Rubbing) Alcohol, I would recommend a rubber cement thinner like "Bestine", found in art supply stores.