Good stuff! A friend of mine who i had just rang was about 2 minutes from getting a 2nd hand motor put in, because of a smoke cloud coming out of the exhaust on a newish car he bought.
And this problem started not long after he did an oil change and using an engine oil flush treatment.
Thought he had stuffed the motor.
So I told him to disconnect the breather line to the intake, and take it for a good blat.
Sure enough the smoke slowly faded.
Went to his house, ripped off the cover..... Sure enough his looked like yours did.
The engine flush loosened all the crap on the cover and around the baffle, and was getting sucked up through the breather.
Saved him $5 grand!
Cleaned it up, put a $15 catch can in the line. A few cans of cleaner, and new plugs.
Presto!
Good chance you will have some soot and gunk in your manifolds and around the valves and in the exhaust pipe.
Give it 100kms, then pop your plugs out, dump a full can of cleaner down the throttle, let it sit for a minute, crank to move valves, as some will be closed and not get a soak etc , then give it another full can . Then get a friend to crank it for you whilst you use an air pistol down the throttle and cover the gap with a rag to stop the air getting out past it. Then do the same into the pots, give each pot a spray/soak, crank , blast into pot, don't put the tip of the air pistol to far in!
Refit your plugs , run till warm, then use the cleaner down the throttle in the standard way,.
Go for another blat to spit it all out of your exhaust system.