Well, it took him over 24 hours to recover from his first exposure in canon, and that did not involve imbeding of Kryptonite in his skin.
THe trace amount in Diana Stride's lipstick would have killed him except he got intensive treatment at the hospital.
In this case he had Kryptonite embeded in his skin for hours.
Somehow I think if there was any left he would be hurting stil. Although I could be wrong.
Anyway, there have been stories where Clark took a whole month to mostly recover. So he seems to heal at the speed of plot, so for now I am going to assume that is what is going on here. There is no reason for him to recover, so he is not.
Hmm, maybe his recovery of powers at extremely fast rates is driven by sensing a need to do so.
