I've never tried 24/7 lights on pullings or flower stalks, but what would concern me is not enough downtime to process the light (which occurs at night); I'm not sure if pullings/stalks have this requirement, so I'm a little wary on that front. If you don't get a reply from someone who has done it successfully, you may consider using a 16/8 cycle to be safe.
If you do keep the light on your pullings/stalk 24/7, yes switch to 16 hours on/8 off when you see the plantlet(s) start coming up, and please let us know how it goes (e.g. time taken to see plantlets).
Edited: I found this thread
, which contains a discussion with the following quote from Matt, which points towards sticking with 16/8 rather than 24 hours:
...If you treat your pullings the same as your plant, they will take. There's really not any reason to do much of anything special to them and certainly putting them in pure water is nothing more than novel, and it certainly won't increase your chances to get a strike. It helps to put them in sphagnum, but pure water isn't necessary at all.
If you want to keep the humidity high, use a ziplock bag or a plastic container with a lid that you can close. Pullings seem to strike well even with ambient humidity if you use sphagnum.