In Japan, confessions are intended to work as you suggest:
>Article 38 of Japan's Constitution categorically requires that "no person shall be convicted or punished in cases where the only proof against a suspect is his/her own confession," In practice, this constitutional requirement takes a form of safeguarding known as the "revelation of secret" (Himitsu no Bakuro, lit. "outing of secret")...
>...for confession to be a valid evidence for conviction, the Japanese court requires confession to include revelation of verifiable factual matter that only the perpetrator of the crime could have known about, such as the location of an undiscovered body or the time and place the murder weapon was purchased, a fact about the crime scene, etc. Furthermore, to safeguard against the possibility that the interrogator has implanted such knowledge into the confession, the prosecutor must prove that such revelation of secret was unknown to the police until the point of confession.
>Article 38 of Japan's Constitution categorically requires that "no person shall be convicted or punished in cases where the only proof against a suspect is his/her own confession," In practice, this constitutional requirement takes a form of safeguarding known as the "revelation of secret" (Himitsu no Bakuro, lit. "outing of secret")...
>...for confession to be a valid evidence for conviction, the Japanese court requires confession to include revelation of verifiable factual matter that only the perpetrator of the crime could have known about, such as the location of an undiscovered body or the time and place the murder weapon was purchased, a fact about the crime scene, etc. Furthermore, to safeguard against the possibility that the interrogator has implanted such knowledge into the confession, the prosecutor must prove that such revelation of secret was unknown to the police until the point of confession.
https://en.wikipedia.org/wiki/Criminal_justice_system_of_Jap...