This thread caught my eye because mine started doing this about 30K miles ago, and once it warmed up the tick went away. I figured it was either a lifter bleeding down or somehow a piece of trash or carbon got caught in the pushrod. I tried several different brands of oil and filter, MMO, Sea Foam, you name it. Nothing got rid of it permanently, but Rotella did make the intervals it didn't tick last longer.
Cracked compression ring was the culprit. I drove it with the tick and didn't have any performance loss for a long, long time, but oil consumption began to creep up and then it started misfiring.
I'd do a cylinder leakdown test and a compression test just to eliminate those variables. That's how I discovered mine; all the cylinders were in fine shape but the number five, which had 80 psi. All the additives in the world can't fix a busted ring, which is what I fear you have. Unfortunately a busted ring eats the cylinder wall, so a rebuild is necessary.
If the tick never returns, that's great. I hope it was just something lodged where it shouldn't have been in your case.