Doesn't necessarily require detergent and that may make it worse - but if the drink contained protein or fats/oils then it may be necessary in order to get rid of all the gunk. If you do need to use detergent, dilute it with dH2O (distilled water) (about two or three drops per cup of dH2O should do it), not tap water - rationale to follow. dH20 costs less than $1. per gallon here.
. The following method will work well on drinks or residues that contain mainly sugars and other carbs: I recommend a soak of the affected keys in very warm dH2O followed by a rinse with yet more very warm dH2O. dH2O because we don't want any mineral solutes from the water depositing on the electronics. Also dH2O is called "hungry water" as it will more avidly dissolve and absorb more solute than tap water.
. After you've shaken and drained as much of the water as possible, give it yet another rinse with 70% or higher isopropyl or ethyl alcohol which will pick up and carry away any remaining water. Drain and shake as much alcohol off as you can and then let it air dry overnight - alcohol evaporates with little or no residue.
. If you are comfortable disassembling your kbd before the cleaning process (they are really very simple devices unless you have one of those older IBM, Chicony, Alps etc. that used mechanical key switches), the results will be a lot better and you won't need to use as much dH20 and alcohol.
. See how that works - but as others have implied, it would have to be a pretty sweet kbd before I'd be willing to take the time when new kbds are so cheap. OTOH, I'd just about go to the ends of the earth to keep my original Logitech Trackman Marble FX working...
.bh.