This website contains age-restricted materials including nudity and explicit depictions of sexual activity.
By entering, you affirm that you are at least 18 years of age or the age of majority in the jurisdiction you are accessing the website from and you consent to viewing sexually explicit content.
I have never seen the term used the way you describe. Because doing that is definitely not doing your job and grounds for termination if they ever found out.
Hence the quietness
… yeah. That’s the “quitting” part. You aren’t doing your job, but you are quiet about it so you keep getting paid. That’s what this phrase means.