The word on the rules posted outside the parks state that handheld extension sticks, such as selfie sticks are prohibited. Looking at the pictures of these things, I think you would be hard pressed to convince them to allow these into the park, as I don't see how you would be able to convince them that it isn't a handheld extension stick.
Also, please remember that just because you were able to get it through security doesn't mean it is allowed, I have seen people kicked out of the park after having somehow sneaking a selfie stick in and they did not get a refund on their ticket and were not permitted back in since they intentionally broke the rules.