In Episode 9 (Charlie Chuckles) in T-Bag Strikes Again when Charlie Chuckles does the trick with the coloured pom poms.
Charlie Chuckles: ‘Now watch carefully. The yellow pom pom’s attached to the red pom pom and the red pom pom’s attached to the white pom pom and the white pom pom’s attached to the blue pom pom and the blue pom pom’s attached to the yellow pom pom but also the yellow pom pom’s attached to the white pom pom and the white pom pom’s attached to the yellow pom pom. Now Sir, if you pull down the white pom pom (T-Shirt pulls down the white pom pom and the yellow pom pom stays still), I thank you. Ahh I know what you’re thinking they’re joined in the middle and you’d be absolutely wrong (Charlie Chuckles pulls the adjoining pole apart). Right ahh come on now you have a try.’
I still don't know how it's done but while going through the credits it says the Conjuring tricks by courtesy of Davenports Magic and I've found their website DAVENPORTS MAGIC and they have the expanding red ball which doubles in size that Charlie Chuckles shows T-Shirt how to do it. Unfortunately they don't have the coloured pom-poms.