First, the video of Packbots' cleaning operation on November 18 of the guide rails to the Containment Vessel hatch in Reactor 3 reactor building 1st floor. As one Packbot wipes the rail and holds the towel up in the air, you see the water is dripping. The droplets look clear, and not sludge-like.
By the way, it is false information that the video was taken by a human worker on the scene. No way even TEPCO would knowingly send a carbon-based worker to videotape in 1.3 sievert/hr (as of November 14) environment. (Human workers entering and finding high-radiation spots is another matter.) One Packbot did the cleaning, while the other videotaped the effort by its colleague. Both were remotely operated by carbon-based colleagues from the PCs.
And here's the video where Packbots went back the next day (November 19) to the guide rails to inspect the cleaning job and measure the radiation again. We know that they found out their cleaning operation didn't reduce the radiation levels along the rails; the levels went up (see yesterday's post). The guide rails, despite the cleaning operation, look wet: