I think Alcohol is fine compared to pesticides mate because alcohol is wont leave any stain inside your board not like pesticides that has other compound that may harm your internals.

Just like what @peter0425 says make sure to Blow air right after you sprayed so it will dry faster and also Unplug it first before doing such.

I have same problem in my laptop's keyboard in last year and this is what i did luckily they all died and never comes back again maybe because of the scent of alcohol that remains inside.