If you look at how the disk platters are mounted, you might think it’s impossible to get in between for a good cleaning. Not so! Take some dental floss and thoroughly clean out those tight spots to get all those lost bytes, pieces of pizza and other junk that can accumulate in your drive over time.
Then get the toothbrush one more time and give the read/write heads a thorough scrubbing. They have to be clean when they scoot across those platters to ensure optimum efficiency when opening and saving files.