Simply remove the valve and spray the cleaner into the openings while blowing compressed air into the inlet port ... One ...

Separating the crankcase from the intake manifold, which is a source of varying air pressure, the PCV valve maintains the optimal level of vacuum in the crankcase to extract the products of blow ...

[Tom Stanton] has designed and made a couple of air-powered 3D printed engines but ... while the pin pushes open a ball which acts as the inlet valve to pressurize an intermediate chamber.