Hello there,
There are different methods/timing for w2s and different things work well, just depends on your lo. However, Tracy's method of w2s involves just the slightest stir--just enough to restart the sleep cycle, but ideally not enough to wake the lo or that they will need assistance going back down after doing w2s.
I do use a paci and am not against them. Using it for nap extension MAY be fine. However, in the event that the paci becomes a prop and you need to wean, you might get some regression with naps. I personally would work on nap extension techniques (pat/shhh or w2s) that do not involve a paci. That way you know that whatever happens with the paci, whether you continue with it or stop using it, you won't mess up naps.
We had success extending naps by going in and patting just before she stirred to get her into the next sleep cycle. At first it often did take up to 20 minutes, but the time patting got shorter and shorter, then we got lazy and didn't go into her room until we heard her, then we stopped needing to go in at all. It takes awhile but it does work as long as A times are right.
HTH!