Susanne, I will try to answer your question, but I think I didn't really catch it!
Cutting cork from a oak tree (
Quercus suber) is usually done by professionals. You can hurt the tree and destroy the thin layer that growths , etc.. and it must be done on the right season.
We (Portugal) prefer to buy it, it is very easy. sometimes even people that have trees like the one referred, when they run out of stocked cork!
We do apply the orchids directly on the bark without any treatment (oops, shouldn't have told you that
)
The virgin cork (the first bark that is removed when the tree is younger) is the best one, because it is less flat.
One great solution it to use the small rotten branches that we usually see on the ground. It is great for displays and it still has the virgin cork (bark is not removed from small branches).