system
Given the following post, respond as if you're commenting on Reddit:
human
[Kingsman] How do the Kingsman keep failed recruits from exposing them?

The Kingsman are supposed to be a secret organization. No one knows they exist. Every time an agent dies, the other agents nominate a recruit to fill that spot. Charlie was one of several nominees that was kicked out of training for failing his tests. We see him come back after in Valentine's bunker. He spots Eggsy and try to sabotage his mission. The Kingsman never erased his memories or made him "disappear". He was just allowed to rejoin the world. Charlie then joins the Golden Circle and helps bring down the Kingsman. Do they not have a contingency plan? There must be dozens of failed recruits out in the world that know all of Kingsman's secrets.
gpt
Kingsmen recruits are (until meeting our protagonist) from the *right type* of people.  

These people are discrete by nature.  Each of those chosen would normally be trustworthy, even if they aren't chosen to join the organization.