The bass strings on a classical guitar often go dead before the trebles. The strings are usually not worn out. The windings are dirty. Remove the bass strings only. Loosely coil them and place them in a large basin, bathroom sink or whatever. Submerge them in room temperature water. The water can be lukewarm but NEVER HOT. Hot water will cause nylon guitar strings to play out of tune.

Add about 1/4 cup of ammonia to the water and let the strings soak for about fifteen minutes. More time won’t hurt them. The ammonia and water mixture breaks down the crud that has built up between the windings on the strings. Put a washcloth in the water and pull each string through it a couple of times. Rinse the strings under cold water. Pull them through a dry towel and put them back on your guitar.

The cleaned basses often sound better than they did when new. They don’t squeak as much and they don’t need to stretch out like new strings. The washed strings also work well for recording because they are somewhat smoother since they have been played in and they have a lively, clear sound.