Originally Posted By: addyguy
If the bottle is sealed, his fear is unfounded.
I've used 1998-vintage SJ oil in the last couple of years w/o issue - oil and bottle were as clean as a new one. Just pour it and go!
+1- Shake it up and pour it in, shaking shouldn't even be necessary but it won't hurt. If he wants to filter it, use the funnel filters painters use to strain paint before adding it to a sprayer, they work extremely well. HTH