Fifteen years ago I moved, and I gave away most of a fairly considerable orchid collection, including some large Cattleyas. One of my favorites was a huge clump of SLC. Jewelbox 'Dark Waters', a beautiful deep red from the 1960s. I did, however, take with me a single pseudobulb; a back bulb that had broken off the parent plant. It has no roots whatsoever, and I set my expectations on "very low". I put that lone rootless pseudobulb in a ziplock bag with a handful of barely damp sphagnum and hung the bag on the wall in a bright (no direct sun) place and commenced to ignore it.....
......for a full year.
One day I opened the bag because I noted that it wasn't dead yet (surprisingly). Not only had it not croaked, it had started a few 1/2" roots and a dormant node had begun swelling! Fast forward fourteen years: that plant is now in a ten inch pot, spilling over the sides, with probably close to 70 pseudobulbs. Last February it produced 18 bloom spikes with nearly seventy blooms.
So, depending in how much you want to invest into nursing what sounds like a pretty badly damaged Cattleya, you can probably recover it and make a decent plant out of it. It all depends how much energy/time you want to dedicate to the cause. For me, my Jewel Box had sentimental value and was worth the effort. A six dollar garden center discount orchid may not be worth the effort though. You make your own choice. For six bucks, you can afford to throw it out and call it a lesson learned, ya know?
This is SLC. Jewel Box last year. Unfortunately I didn't get a photo of the whole plant in bloom; there were many more blooms than what you see here: