When I water, I use only water. I foliar feed 2-3 times a month in summer, and I use a tiny bit of slow release fertilizer in the pots.
Regarding cnycharles comment above, I grow Mexipediums hot, humid, and bright!
FWIW - When I use those clips, I put the tips of the claws around the flower stem. If you look at the inside/base of the claws some clips have blocks, and others have a very narrow angle, that might pinch closed and cause problems?
Did the plant get too dry while attempting to bloom?
As mentioned above, the Brachy X multi hybrids are problematic and I agree with blooming it 1-2 times more to see what it does. Too much potential to not try again!