The plants I have growing in rock prefer less water, anyway. They are Laelias and are specifically rupiculous (thriving in rocks). My catts have all done far better in a bark mix, so I would probably repot into bark. I tend to water more frequently as temperatures soar, so that may not be so helpful for you in this case. I watch root growth as an indicator of overall plant health. Not too regimented, but it's worked for me so far.
Good growing to you,