Oil gunk in intake - 1997 4runner

[etc.]

I have a 1997 4runner w/3.4 and 229,030 miles. When I first did the valve cover gaskets 5 years ago, I noticed oil residue in the intake. I bought and installed a catch can, which has worked wonderfully. Fast forward to a couple weeks ago, I pulled the intake again and noticed the old oil in the lower intake has hardened and I fear it may be playing with my performance and efficiency.

I'm looking for ways to remove the gunk...short of removing the lower intake manifold. I was originally looking at Amsoil Power Foam, but that looks like it's targeted towards carbon. I suppose I could also benefit from some carbon removal.

Thank you in advance

 

[KingCake]

It won't hurt anything. Carb cleaner or some ac/delco upper engine cleaner will work. BBK emission cleaner too.

 

[Ducked]

Petrol. Get it while its cheap

 

[Olas]

Carb cleaner and/or brake cleaner down the inlet while it's running. Be sure to stand upwind

 

[ARB1977]

Three months ago I ran a can of sea foam through the intake. A few week later I removed the throttle body to clean it. The top intake manifold looked spotless. Unfortunately I don't have before results.

 

[etc.]

Do I stand a chance at fouling plugs if I use brake or carb cleaner?

 

[Olas]

No chance at all - keep the engine at around 2500 to 3000 rpm and sprat down the inlet in short bursts.
For visual confirmation put a sheet of paper behind the exhaust and look at all the [censored] stuck to it afterwards

 

[CBR.worm]

Some brake cleaner is extremely poisonous if burned. Be sure to look at your MSDS