A dirty touchpad can not only affect the look of your laptop but cause sticky fingers or erratic responses. There's no reason to avoid cleaning it when you likely already have the necessary supplies at home. Touchpads aren't so fragile that they can't withstand a basic cleaning, so grab a couple of supplies and drop a little elbow grease. Before you know it, you could have a touchpad that not only looks better but works better.
Turn off the power to the laptop. You can also unplug it and remove the battery to avoid any potential short of the system or shock to you.
Dampen a cloth lightly with the distilled water. Dab off any excess onto the second cloth or dry part of the same cloth. Rub the touchpad with light pressure to remove the dirt. Dry with the second cloth.
Mix one part distilled water to one part isopropyl alcohol in a bowl or cup for a stronger cleaning solution if necessary. Moisten the cloth with the solution and rub the touchpad with light pressure. Wipe dry with the second cloth.