I tried the Blue Wonder and wasn't overly impressed with it. It's really stinky & slimey and gooey to work with............definitely for outside the house cleaning only.

I come to really like the MPro-7 cleaner. http://www.mp7.com/

It's odorless and does a good job on powder fouling - leaving the bore prime for lead or copper removal with a solvent specific for them.
And I prefer Sweets or CR-10 for the copper.

And for after-cleaning oil & preservation, I like either BreakFree CLP or Militec CLP ( http://www.militec-1.com/ ).