Which of the following solutions is better for the following goal:
To keep cake moist when rolling.
While still warm, start rolling the sponge with the help of the parchment paper sandwiched in between the sponge. You could also use a kitchen towel or a clean cloth to help you roll easier but it's not compulsory. Roll tightly and tuck the edges of your parchment and/or kitchen cloth to keep it moist.