ORA-01503: CREATE CONTROLFILE failed on RMAN duplicate between RAC databases

It was while since I performed an RMAN duplicate from a RAC database to another RAC database. You may find this post useless as there’s a lot of information out there about the error I faced, but all my posts are kind of my own little diary.
So, basically. In order to successfully duplicate one database to another you may need this.

    – TNS setup on the server where the database to be duplicated is hosted. You need to be able to tnsping both, the target and the auxiliary database.

     – Create a parameter file and password file for the auxiliary and startup nomount the first instance.
    – Create a full backup of the target database including archivelogs.
    – Connect to rman to both the target and the auxiliary databases from the auxiliary server:
rman target sys/*****@ auxiliary /
    – Issue the duplicate command:

 duplicate target database to ;
This should successfully finish but I got this error:

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 01/03/2017 18:29:58
RMAN-05501: aborting duplication of target database
RMAN-06136: ORACLE error from auxiliary database: ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode
I searched this and the culprit is that my parameter file for the auxiliary had this:

cluster_database = true

By MOS note “Rman duplicate fail with RMAN-06136, ORA-01503, ORA-12720, ORA-00494 enqueue [CF] (Doc ID 1335479.1)”. Duplicate from a RAC database to another RAC database is not supported, hence we need to modify the parameter cluster_database to false in the auxiliary database.
After doing this the duplicate finished correctly.
Thanks,

Alfredo