You mention "oily residue".....How long are you leaving this stuff on your weapon? How thorough are your cleaning methods? Ive been using Hoppes 9 for years now and have yet to encounter this "residue."
Once a coat of Hoppes 9 has "done its thing," I thoroughly remove it with numerous patches (using a jag), clean rags and if necessary, Isopropyl alcohol (92% or better). Then, I wrap things up with a fresh coat of Weapon Shield. No residue left..just WS oil.
Its been my (somewhat limited) experience that, more often than not, when the weapon surface seems too slick or oily, its simply due to excessive amounts of cleaner and/or lubricant being left on various surfaces. One should be as thorough as possible when wiping off solvents and other cleaning agents. In terms of oils/lubricants, if you can leave a fingerprint with just a very light touch...you have enough oil, IMHO. Anything more than that is just an invitation to excessive amounts of lint and/or other accumulated debris.
Oh, and the smell of Hoppes 9? I love it.