I think the answer is that they all had to. Marlyn Monroe had to, and she was a bigger star in her time than ms WelchI saw a documentary about Hollywood in the 40s 50s and 60s. The big shots had what were called 5 O'clock girls. These are the girls that are signed on at the studios and paid a salary to be extras. They had to wait all day at the studio on standby and were paid a very good sum to wait, but by no means star money. These girls were waiting for their big break. The girls that were eager for stardom offered themselves to the big shots at the studios by waiting at the commissary to be asked out for dinner and drinks and the casting couch. Some of these girls would be called for costume screenings at the big shots office as an excuse for some mid day relief.
I wonder if Raquel ever had to do the casting couch?