basket covering ?

[swiatoniowski]

I should start growing some of the Stanchopea alliance quite soon, however, I have some problems to decide the medium. I prefer growing orchids in Leca-like substrat to organic matter. Of course I have to cover sides and bottom of the basket with sphagnum or coconut fiber. The question is if I can use some artificial material similar to sphagnum but not organic ? Do you know any ? I looked for mineral wool, but I think it is too dense for flower spikes...