If your guitar becomes cracked anywhere for any reason, bring it to a trustworthy repairperson. Your instrument was not designed to sound at its best or maintain its structural integrity with cracks in it. Very few people have such acidic sweat that lacquer becomes damaged, but it happens. Keep a laundered soft towel or rag available to clean your instrument after playing it. Good commercially available guitar polishes are also available to help protect your guitar finish.
Routine maintenance is the key here.
The damp sponge or humidifier won't do any good when the water is gone from them. The cleaning cloth that is soaked with sweat isn't doing what you wish it would. Play it and give it a little help, and that effort will make a positive impact on your music. And that is what this is all about. All Rights Reserved.