I suppose you could use it like a T-Bar. They rely on the wieght of the fish pulling the barb out. They work like this.My Vic Huntsman had a hook next to the awl/stabber. I believe it to be a fish-hook disgorger, but I'm not sure how it works.
Hold the line not the fish. Hook the line below your hand into the hook. Pull the SAK sidewards untill the fishook locates into the SAK hook You can now invert the fish hook so that the fish is effectively hanging from the barb.A quick shake should release it.
This type of disgorger works best with bigger hooks and bigger bait and is usually used in sea fishing. I think if you did it on a carp lake you would get lynched!