Traditionally, a plant’s roots are encased in a ball of soil, which is covered with a layer of moss, forming a sphere. To display the kokedama you can hang it, or set it on a saucer or plate.
First, phalaenopsis orchids do not have water storage, so they like their potting media to be slightly damp – not wet. Sphagnum moss – the media used to wrap the orchid’s roots – is highly absorbent.
Second, I recommend placing a wiffle ball or a styrofoam ball in the center of the kokedama. This keeps the center of the kokedama dry. If the entire kokedama ball was composed of sphagnum moss the center would have a very hard time drying out. A continuously wet moss ball results in dead, rotten roots in the center of the kokedama.
In other words, an outer layer of sphagnum moss wrapped around the phals roots combined with a hollow, or non-absorbent center, results in a dry center in the moss ball with a damp moss ball exterior. Your phalaneopsis orchids will LOVE it!