I have used Outers, Gunslick and Wipe Out and can't really tell much difference. They all work well and are pretty much all I use now. I used to follow up with some Butch's Bore Shine or 50 BMG, just looking for some blue on a patch I finally gave up and admitted the foam really did get all the copper out.
I like to fill the bore and leave the can/tube inserted in my bore guide. I let the first bit sit for 30 to 40 min then every now and then I will pass by and give a squirt until fresh foam starts coming out the barrel. I may do this 4 or 5 times over an hour or two. It may be a little overkill, but even with something as strong as 50 BMG I don't get any more "blue".