bunkeroo26- I've removed the oxidation with different things, depends on the trim and the level of degradation.
Sometimes KAIO will do it. When things were pretty bad I've had good results (sometimes surprisingly good) with Hi-Temp's Heavy Cut Leveler (AKA "357")...yep, a "compound" made for paint. It doesn't stain the trim white, at least not as long as you wipe it off before it flashes. I keep a bottle of 357 onhand just for this application.
Another product that can work *VERY* well for this is Griot's Rubber Prep (used this on some nasty trim on the older Crown Vic, think "left outside for ages in FLA", and then topped with the Ultima with wonderful results that have held up great).
I usually protect the trim with KSG (especially if I cleaned it with the KAIO) or 845, but these days I lean more towards Ultima's trim sealant (it's named "Tire and Tirm Guard Plus" or something like that). Then I maintain with ValuGard's Fast Finish between major redos. No running/etc. in rain, long-lasting results.
I hardly *ever* use the dressing approach unless the preceding just won't work (usually because the trim is too far gone), but when I do I use AutoGlym's Bumper Care, which I find utterly superior to other exterior trim/rubber products that I've tried.
If the trim is in really bad shape, restore it with ValuGard's Exterior Trim Restoration kit, which is currently in it's second or third version ("ETR II" or "ETR III" on the ValuGard website). The ETR stuff is *the* industry standard for this kind of thing.