Removing blob using pure JDBC (PG7.1)

Hi,

The documentation from jdbc-lo.htm shows how to create and read a blob
object using pure JDBC calls (that is, without using the
org.postgresql.largeobject.* package).

Since the documentation doesn't show it, how can I remove a blob ? Does
a setNull() to the oid pointing to the blob do the job ? (Will the
driver intercept this and make an "unlink" ?)

Or should I stick with 
LargeObjectManager lobj =
((org.postgresql.Connection)dbCon).getLargeObjectAPI();
lobj.unlink(oid);
?

Thanks ...