Thanks for the suggestion, Dennis. I had forgotten this trick.
This was from a NY Times article for 1977:
Jun 12, 1977 - Wet them down with a final syringe of clear water and then seal the bag shut. Keep the bag in good light, never sunlight, as this would make leaf transpiration much too rapid and rot the cuttings. Also, be sure the bags are in a warm place, not by a windy breezy window. Check the bag every few days.
Here is a step by step explanation:
https://www.missouribotanicalgarden.org/