> Could anybody provide an insight on how to properly close embedded
> connections and clean up caches without shutting down the JVM?

You close the embedded connections the same way you close "normal"
connections.

I suspect there is no chance to clean the Firebird Embedded caches
without shutting down the JVM - the Firebird Embedded on Windows is
based on SuperServer architecture, cache applies to process, not to a
particular connection.

Roman