Restart - simple with known and predictable effects, data no longer accessible, all secrets flushed no matter where they were or cached.
Turn off disk encryption, suspend all running services, overwrite all secrets in the O/S wherever they are, and then restore all that on entering password. Probably can't do anything about secrets cached by actual apps.
Complex, hard to maintain and probably buggy.
Restart - simple with known and predictable effects, data no longer accessible, all secrets flushed no matter where they were or cached.
Turn off disk encryption, suspend all running services, overwrite all secrets in the O/S wherever they are, and then restore all that on entering password. Probably can't do anything about secrets cached by actual apps. Complex, hard to maintain and probably buggy.