Oatmeal Vanilla Stout - fermentation question

[MasterBlaster]

Quick question for you all:

I've brewed a partial mash version of the DuClaw Oatmeal Vanilla Stout. It's been one week in the primary carboy. The instructions tell me to split the vanilla beans and drop them in the secondary without any details about the durations for primary or secondary.

Does anyone have any experience with this recipe? How long should I leave it in the primary and how long should I leave it on the vanilla in the secondary?

Not enough vanilla is okay. What I really want to avoid is getting odd or off flavors from leaving it on the vanilla too long.

Thanks,
-Patrick
(SF Bay Area)

[MasterBlaster]

Follow-up for anyone interested:

I did two weeks in the Primary before moving to the Secondary. In the Secondary carboy I included 3 split vanilla beans (as directed by DuClaw's recipe). The recipe did not specify the time it should be kept on the vanilla so... I decided to give it 2 weeks.

During bottling I gave it a taste (don't we all). The vanilla flavor was VERY strong. I'll open a 12oz bottle after 3 or 4 weeks and see how it progresses and then try it again after 8 weeks. My hope is that the vanilla moves into the background. If not, this beer will be mostly poured over ice cream.

-Patrick