He was referring to Mary Magdeline, who was not a disciple. Also Jesus ministered to harlots at that time to forgive their sins and give them a second chance.Doesn't mean they can't be gigolos
Harlots of that time were often on the fringes of society, seen as unclean, and treated with contempt. But they had no man to take care of them, were likely divorced and had to do that in order not to starve to death. A much different situation compared to today where its glorified in feminist society.
Jesus said if a man looks with lust at a woman then he has committed adultery in his heart and is at risk of damnation. (Matt 5:28). To make such a suggestion about His disciples is beyond absurd.