I've always used straight Flouro, Trilene 100%. Just recently switched to Power Pro 30LB braid with a 3Ft flouro leader to give it a shot. Straight flouro does, IMHO, give you much better feedback to bites then a braid/leader combo. There is no wrong line to use for senkos. I have used Mono, Flouro, and braid...all with varying degrees of success. Good luck in your search for a good senko line!