Even the pine version of SKCM black isn't lubed, only the really early switches are, and SKCM black is one of the youngest in the line.
Thanks. I cleaned them without waiting for a reply. Three days later the job is done. Before I started the keyboard, a last generation black Dell AT101, had little drops of white paint all over it and the switches felt very scratchy. I painstakingly removed every paint drop and then cleaned every switch. Many tactile leaves had visible wear on them, so I wasn't expecting great results. I also did the paper mod, because some switches were clicking on the upstroke after reassembly. I used very thin Washi paper, cause I didn't want to change the tactile feel. It worked.
Now the switches feel much better. They are still a little rough, but although I never used a new bamboo SCKM black keyboard, I read and heard they are not supposed to be perfectly smooth. So I guess, the restoration worked, at least to some extend. Here is a picture: