Alternative Way of Putting Your Damper

Here's another way of putting the damper on your Erhu.

You fold it and insert it in between the strings.

The idea is that the unwanted noise comes from the part of the string between the bridge and the base of the Erhu. So putting the damper there reduces the noise. The Erhu will sound less muted than if you put the damper under the strings because there is much less pressure on the snakeskin.