Touching up anything frame by frame is not only tedious, but can also reveal inconsistencies when played back real time. Off the top of my head, I would suggest looking into AE’s clone tool. Although, I’ve been trying to find some info on revoming human skin blemishes and wrinkles as well. Someone should write an extensitve tutorial on this for After Effects. I know it can do it, but I haven’t had the time yet to get into experimenting. Hopefully someone else out there uses it for that and can tell us about their techniques. I imagine it’s a combination of tracking a cloned area and masking. I look forward to responses.