Permasink is a "mud" that degrease's the leader and helps it to cut through the surface tension of the water. There is no magical solution to making a leader cut through the surface tension apart from regularly applying mud to the leader to remove 'grease' from the line and help it to cut through. When dry fly fishing you want to apply mud to the last few feet of your leader/tippet just before the fly to get the leader to sink next to the fly so that the fish cannot see the leader on the surface of the water
Comes in a glass bottle