It looks about the same inside the head as far as I can see though it is difficult. However I feel around the hair inside and it was all sticky with glue. I've not felt sticky got inside a pony mane before
I can post pictures later today
Another vote for 'looks like genuine hair to me'. Sounds like that Show Sheen stuff might be the culprit and you'll just have to keep washing him until it's all gone. Argh, why do people put sticky products like that on ponies?