How To Clean A Circuit Board Without Alcohol. If the spill has started to dry, dampen the towel with a small amount of rubbing alcohol, squeeze out most of the liquid. For a more thorough clean, put some 91% or 99% pure isopropyl alcohol in a spray bottle, then spray the board down with the alcohol.
The second foremost important factor, that you must consider the temperature of the devices. The other is using a special circuit board cleaning spray. Swab gently in stubborn areas and be careful not to upset the components.
Do not use the rubbing alcohol that you used for the circuit board because it can remove the ink writing on the buttons, as well as cause the rubber to dry out and deteriorate.
It is easy for dirt or dust to get into a printed circuit board and just as easy for that debris to render the device containing the pcb unusable. Take a clean soft toothbrush and dip it in alcohol; 6 clean any residue off the circuit board using a cotton swab. Wipe with a paper wipe to get the majority of the solvent off.