Repotting oncidium alliance question

[Judi]

I finally got the hang of growing oncidium alliance orchids--now I have an other problem. It was time to repot 2 oncidium noids and a Mtssa Royal Robe Jerry's Pick; I last repotted them 2 years ago. Over the last 2 years they developed a lot of new p-bulbs and roots. I soaked the pots for a few hours, took the plants out of the pots--actually I had to cut the clear plastic pots off--then I soaked them overnight to try and get some of the old medium out from the roots. To no avail, I would have damaged the roots if I didn't quit. So I repotted in a larger pot and just put oncidium potting medium around the root mass. Question: am I flirting with rot by not removing the old potting medium ? I couldn't even get into the middle of the root mass where I usually find the old medium and possibly dead roots. I didn't really have a choice, but I am worried. I finally conquered root rot and have healthy chids, but did I do the right thing? Anyone else have a similar dilemma or advise?