I don't use the stuff...Well haven't used it for years. I just don't like the bitterness!
I don't know of any way to cut the bitterness. I certainly have never heard of any way.
It is often stuffed with pork and steamed or boiled. Most people will just remove the pork for eating and discard the melon.
If you are using it for medicinal reasons, then you should be able to get it in a liquid or capsule form from a health food store.
I hope that helps