Spraying is good for an external leak, BUT will not reveal a leak from the crankcase side.
To check that , you need to pull the pcv from its fitting and block the hole with a plug. Then on the vent side plug in a vacuum gauge. It should build a small amount of pressure due to blow by , even on a healthy engine, if the gauge goes into a vacuum, that would indicate an internal leak from the crankcase side.
Fact is stranger than Fiction