I use after run after I clean an engine or before I plan to store it for a period of time.

What I do is take the glow plug out and the muffler off. I then put a couple of drops of after run down the carb throat, 3-5 drops down the glow plug hole and a couple of drops directly into the cylinder thru the exhaust port where the muffler has been removed. Then I just turn it a few times to give the oil a chance to work its way thru everything.

If you're going to store an engine for a while, its probably best to seal it up in a zip-lock type bag to keep air and moisture out of it.

After Run is just what its name says - use it after a run.

Hope this helps,