Rattlin' like a diesel

Apparently, a lifter is sticking and my truck kind of sounds like a diesel. Is there a way to get the sticking lifter to unstick without replacing it? Any kind of oil or gas additive that will actually work to clean the lifters?

Shoving this one back to the top to see if anyone has any suggestions. Any news, good or bad, would be much appreciated.

Many people have used Seafoam, and have had great results.
Not sure if they used it for your exact scenario though.