I don't recommend isopropyl alcohol. It works great on metals (to clean TIM off CPUs and heat sinks, for example) but alcohol is a solvent.
Circuit boards are typically coated with polymeric films, resins or similar coatings to help keep moisture and oxidizing air away from the circuit runs, component leads, PCB substrates, copper and other materials subject to corrosion and/or damage from moisture exposure. This "
conformal coating" also helps isolate ESD sensitive devices from damage from ESD. While there would not be conformal coating on the contact pads themselves, it likely is on the surrounding PCB as well as the dozens and dozens of discrete components in the center area of many CPUs (including the OPs as seen in the screen shot above).
Plus, how would isopropyl alcohol be applied? It does not come (at least not in pure form) in a spray can. So it would have to be poured on (

No!) or applied with a cotton swab or ball, or a cloth, or brush, then "scrubbed"

. Those contact pads are made of gold alloys. Gold is soft. Scrubbing scratches. CPUs are highly ESD sensitive. Scrubbing can create static charges. Alcohol is a solvent that may or may not eat away at the conformal coating.
Since alcohol is a solvent, and we don't know what type of conformal coating is used here, it is best to use something actually designed for electronics - such as quality
electrical contact cleaner as I mentioned above. Plus, the electrical contact cleaner comes in a pressurize can. The force of the expelled cleaner can help "scrub" the dirt and contaminants away without any rubbing. It would be similar to running your car through a "touchless carwash" that uses jets of soapy water instead of one that uses spinning cloth strips that scrape

across the paint and grind grit into the shiny finish.
Use the "
right tool for the job" and avoid the potential risks of damaging the processor. That tool is
electrical contact cleaner.