Need help with Den Aggregatum

[Swamper]

I may change it's name to Den Aggrevatum. I bought this at the Redlands show this year and after all the blooms were gone I mounted it onto a big piece of fern tree that I also got at the show. I noticed now that it still hasn't even tried to attach itself or it seemed that way because when I removed it one single root was attached.
So what is the correct way to mount this one. I removed most but not all the old bark that waas in the middle of the pot and basically mounted it like that. Well maybe this is not as easy as other dens or vandas or catts or anything else I have mounted. The roots still look healthy I guess, I hope they are supposed to be white.
DO I need to remove it all so it lays flat as opposed to looking a little bit moundish if that's a word? Right now I'm soaking it in a bucket of rain water to get the roots softer or plyable.
Thanks for any help out there.