You can do it! I would give it several more tries before going the intake manifold route. If that tech can do it, you can do it! Yes, one clamp was so close to the manifold that you can't get a normal socket on it. The one piece flex shaft driver I had, had a fixed 7mm thin walled socket on it. The tool was made for hose clamps. I think the tech probably used a pry bar of some sort to spin the clamp around. And since the second clamp was the crimp on kind, he probably just pried the hose off.

Good luck,

glenmore