How to pass parameter of user type to remote procedure?

 I want a pl/sql procedure on DB a to call a procedure on DB b, passing a user defined type.  The type is defined identically on both DBs.  Compilation gets "wrong number or type of arguments".

Doing some research, I find (10.1 application developers guide, chapter 7):

"When passing a user defined type, such as a PL/SQL table or record to a remote procedure, to make PL/SQL use the same definition so that the type checker can verify the source, you must create a redundant loop back DBLINK so that when the PL/SQL compiles, both sources pull from the same location."