No, spray 'em out with carburetor cleaner. Most brake cleaner is no longer chlorinated, but chlorinated brake cleaner does still exist, and if it gets sucked into a running engine or otherwise burned it creates severely toxic nerve gas (phosgene) out the exhaust. You do not want to take even a tiny amount of that risk. Carburetor cleaner is the right stuff.
Stuff evaporates so quick that it would be very difficult to get brake clean sucked in to the engine after using it to clean a pcv valve. Let it sit for 7 seconds after you spray it and it’ll be dry as a popcorn fart.
