Hi connie. Yes have used stryo/ polystyrene and also rock wool ( for loft insulation) with success. These kinds of medias are when all else fails for tempremental plants or persistant root rot victims or simply pre empting probs with special specimens. etc. Have a Gramma Spec that has sent its roots right through the stryo/poly chunks without problems infact i think its agressive root growth will end up tearing the stryo chunks up. I have some of my mormodes and catas in stryo for ease and conveniennce and safe assurance against PB rot. They are all sprayed heavily daily. I think more or less everything and anything can be considered as media for growing orchids. I had a stanhopea tigrina growing in an old work boot for years and the hole in the boots sole served as its flower exit route. It had bubble wrap only as a plant root boot stabilizer to stop plant wobbling. It was the boot that gave way first due to rot! Looked fab though esp when in blloom.