Adding the sponge to the hemp rig to increase its buoyancy.
Or can add shot / putty to drop end of hemp rig down further.
The idea of having a small loop at the front of the hair is to gain complete control of how the hemp rig behaves in the water; such as how fast the rig sinks and how its pivots and lays on the bottom.
It's not east to insert a small piece of sponge into a small loop, with a bit of fiddling it can be worked in.
Always add more sponge than required, then you can trim it down until it behaves exactly how you want it to.
Trim the sponge a bit at a time.
Adding sponge to the front loop of the hemp rig increases its buoyancy and will alter how it pivots in the water. If the fake hemp alone causes the front of the hemp rig to pivot too far you can squash on a small shot in the loop. this will drop the front down.
Don't forget to add a flavour to help attract those huge carp!