another timing of repotting question

[nutgirl]

I understand the principle about waiting until new roots are starting to grow in order for them to adapt to S/H....but what should I do when I buy a new plant?

I always take them out of their existing medium when I get them home and would like to change to S/H at that time but they are not always in growth mode. I hate to have to repot with bark because S/H works so well for me. Can I use the LECA as a kind of bark replacement until the timing is right then switch over to the S/H watering regime?

I have 2 oncidium hybrids that are currently blooming but have not started new psuedobulbs or roots.

Am I making this too complicated?

Maureen