Can the TSU3000 hard button contacts inside the case be cleaned with, say, rubbing alcohol and a cotton swab?

One of mine under the screen is going bad. I'm reluctant to take the case apart if there's nothing I can do about the problem.

I can use the label, but that's difficult to press.

Can it be repaired? If so, is it worth it? How about replacement parts?

Thanks in advance for any help!