How much success have you had rooting old rootless Cattleya back-bulbs.

[K-Sci]

When repotting, I recently saved some Cattleya violacea, walkeriana, intermedia, luedemaniana, and tigrina back-bulbs (I collect primarily species orchids). An example is the 9-bulb C. violacea photo I've included.

I'm attempting to root these starting with a treatment of 1tbs/gal KLN rooting agent and KelpMax hormones. No pots, 3x/day drench, 50% filtered sun, and day night lows/highs in my greenhouse are around 70F/92F.

Questions: Is it worth the effort? What should I expect for success? What kind of success have you had rooting old partially shriveled rootless back-bulbs like these? What methods?

K-Sci

Disclaimer: Though I've owned several for some time, the back-bulbs were all pretty shot before I owned these plants.