The other kind of guarding - for things that he gets by accident - that still continues, but less and less, although I don't trust him fully. He has been trained to go in his crate very willingly because he always gets a treat when he does. If he has something I don't want him to have I tell him to "get in your crate!" which almost always works the first time. He gets his treat, I close the crate, and then I clean up the mess without any worry.
For our dog, if it's something like a cookie or pizza, nothing will stop him from devoring it.