Sacking Out Starbuck

The other day I didn't have a lot of time and was feeling pretty under the weather, but I wanted to work at least a little with her so I found a plastic bag and decided to try sacking her out to get her more used to strange new noises and sights.  So she would see the plastic bag as more of a toy and less of a threat, I tied it to the wheelbarrow which she LOVES to play with while I muck out her paddock and she started mouthing it right away.  Then I tied it on my dressage whip and let her get close to it, then would try to rub her neck with it and when she would shy away I would back off and wait for her to come up to it again.  I did this for about 15 minutes the first day before I had to go, then tried again today and spent about 15 more minutes until she let me touch her neck with it, the rest is what ensues in the video!