I think I might give a try of just potting soil and orchis bark and see how the plant reacts. Probably mix in some dead leaves from outside.

So far it is looking good! Mixed about 50/50 orchid bark with soil, mixed in some leaves from outside. I did split it up as well, and both pots are still looking good!

And now that it's done, the Osmocote went on sale for $6.99 (was $15.99!)

I think with Sans you can use any type of soil. The critical aspect is the growing condition: temperature.

Have seen Sans in Manila thriving so well in clayish wet soil, and my mom-in-law says it is the only plant to survive their months long flooding and terrible typhoons. Temps in Manila always hover between 80F and higher. I have also seen a local store in San Francisco growing their Sans near a window in a vase with just water and rocks, but it is indoors. So I think it is the temperature that will dictate more or less how this plant will endure the media it is growing in.

I know this might be a little late but a couple of things to remember about this plant: 1. I will grow in most any little bit of light (the variegated one needs a little more to stay pretty) and can be grown in any soil....the key is water very little. It tolerates dry places and people who kill everything because they forget to water like this one. Hard to kill it even if you overwater. I grow it outside next to the south side of the house in South Georgia and even though it dies back in winter it will come out in the spring. You also don't fertilize it more than maybe 2 times a year lightly.