Watch the video. The guy actually does it a littlesloppy because he should have a vacuum attached. But essentially, there is a specific plastic molding for the Ford 2.0,2.3 intake header ports. This is one on ebay.Bimmers are pretty notorious for this. I'd be very curious also, but I've yet to see someone that has done this on our car.How does walnut blasting prevent the large pieces of carbon from entering the turbo? I would assume it would have to be vacuumed out of the cylinder or something.
Ford Focus ST Ecoboost 2.0L intake valve Carbon Cleaner Walnut Blasting Adapter | eBay
So you essentially fit that piece into the cylinder port you wanna work on, after you have rotated the engine so the valves are shut closed. Then you simply attach a vacuum to the other side, and then use a small diamter wand sprayer to fit into that small hole. Simply spray away and vacuum out until all the carbon is gone. Nothing falls in, because it should all be vacuumed out.
It looks so easy I may try it myself. But again, I'd like to get a look at how much carbon cakes up on these, before I make a decision of how and when.