This may irritate a lot of people, but I have spent a day looking for the answer.
Can an entry in a challenge be withdrawn after challenge is over?? If so, how?
Yes - Just click on your entry and at the bottom right there is a "Withdraw" button. I just tried it as an experiment and it worked fine.
|Blue and yellow in water by fireplace33|
from Ink and water
|Kylmä joki kopio by Kaappo|
from Shutter speed 1/25 or slower
|WR_2.8_13 copy copy by photoprof|