The build-up of grot on your stylus can play havoc with the sound, and a regular clan with the Cleanit brush takes very little time and doesn't need any mysterious fluids. It consists of a handle and a bunch of tightly grouped short carbon fibres. With these stiff little bristles facing upwards, you just have to brush from back to front of the stylus - the direction of the LP groove's travel - a few times to get most of the dirt and acumulated fibres off the stylus. If you don't do this regularly the danger is that the grime heats up and bakes on to the diamond and becomes harder to remove. It also (in effect) changes the shape of the stylus so it doesn't sit into the groove properly, and eventually causes distorted sound. 

As we say, everyone should have one of these. It's just a small thing, but it's the best type of brush for stylus cleaning.