I have an Oatmeal Stout in the secondary fermenter (carboy) and it's been there for about a week. I checked the hydrometer reading this morning and it's at 1.020. The og was about 1.052, and when I moved from the Primary to secondary it was about 1.024. I was aiming for a FG of 1.010. Any ideas? Can I keep in the secondary for another week? Can I gently shake the carboy to awaken the yeast?
Warm it up to 70-75 prior to swirling it to rouse the yeast. Give it another week or two then check it.
Without knowing your recipe and process its hard to really tell. It could be as done as its going to be.
Next time leave it in primary until its at the final gravity. You have less yeast to work with now than you did when it was in primary.
EDIT: So you steeped oatmeal with your specialty grains. You are likely at terminal gravity. The oatmeal contributes unfermentable starch to the wort when not converted with a mash of some sort. That starch will hold up your final gravity considerably.
How were you "aiming for" a FG of 1.010? What was your recipe like that made you think you'd hit that FG? Depending on your recipe, you could very well be done. The advice to warm it up and wait a while is good, but you still might not hit that FG if you used a high level of unfermentables. That makes much more difference than the yeast.
Cooper's dry yeast by any chance? But yeah, you can certainly leave it in the secondary another week or more. It won't hurt anything and may help you get a clearer, cleaner beer.
You can gently swirl the carboy, and as another answer mentioned, try warming it up a bit.