Select All Visible Faces With "Occlude Background Geometry"

I have a very messy model I’m trying to clean up for 3D printing. Basically I’m trying to delete a bunch of internal geometry. I found some instructions online that helped a bit, it involves using “occlude background geometry” to manually select all the visible faces, then deleting the rest. This works, but it takes FOREVER to select all the visible faces with the circle/box/lasso tool. I feel like I must be missing an easy way to auto select all the faces which are visible when the “occlude background geometry” is turned on. I’ve tried selected a few faces then using ctrl+, but the expanded selection also chooses some of the hidden faces. Any help would be greatly appreciated.