I guess it depends how bad it is. If it is out of the car blasting them with the finest glass beads, or baking soda, at low pressure, like 20-30 lbs, and a flush with ideal 40-610 contact cleaner will do the trick. Walnut shells work pretty good on some of the plastic, LOW pressure. I have never been a fan of soaking crimped wire in any acidic solution, if it is that bad a new one would be wise. Never use simple green or purple power on them, stick with lacquar thinner or an eletrical contact cleaner that evaporates fast.
I should be clear, I use size AH, or #13 glass beads, they are .001-.003 size, like dust. The crap harbor freight sells need not apply.
