I have tried it several times, the first using alcohol the second using AL +Hoppes #9 in a 50/50 and the last using Hoppes Elite. when I try it I shot 6 inch gongs at 250 yds for my last target. I shows up some at any range over 50 yds but it really shows big time at 250, the first shot and some times the second shot is off so it is like that first shot out of the gun with that tiny bit of oil you can never get out of the pores.
I tried wiping every shot also and the groups were definitely consistently bigger, on an average about 3/4 of an inch bigger at 100 yds and I much prefer 3/4 inch groups to 1.5 inch groups. This was all done with 250 gr Shock Wave bullets and 120 grains of Blackhorn which is what the Endeavor shoots best.
Now I have no doubt that some where there is a gun that will shoot best swabbing blackhorn but while several of us have tried none of us has that gun.