Electronics "cleaner/degreaser" types of spray come blasting out to give your board a penetrating bath in solvents that evaporate quickly without leaving a residue. They are NOT intended for spraying on live (energised) circuitry as the solvents are flammable!
And of course, no one here would think about doing this while the monitor is plugged in, right?
Right?
What I've done is pull the boards, bring them to the sink, and hose them down. Spray it with a gentle degreaser, wait a few minutes, and hose down again.
All the while, the oven has been preheating @ 150 degrees. Once you're done washing, turn the oven OFF. Get the hair dryer out, and blow the heck out of the board. Then put the board in the oven, and go away. Come back in three hours.