Oracle Database Discussions

I am using rman duplicate to create a clone of a production database. The rman duplicate failed in phase 1 (retoration of datafiles) and my datafile are being restored to an ASM diskgroup.
I read in the metalink note Manual Completion of a Failed RMAN Duplicate [ID 360962.1] the following...
Note : From 10g onwards, if duplicate failed during step 1, which is the restore of datafiles, it is probably best to restart the duplicate process. Any files that have already been restored will be skipped and the duplicate process can continue without manual intervention

So I followed the advice in the note and started the rman duplcate script over again from the beggining. I am hoping it will have the intelligence to skip any files that have already been restored but if it is not since this is 10.1.0.3 and I cannot use the asmcmd command to connect to the ASM instance to delete any files that have been created then how can I delete and of the files since the database instance never got created correctly and cannot open?
Any thought on how I can now cleanup the files in the ASM disk group? Also, has anyone started an rman duplicate again after it has previously failed and did it actually skip the files that are already there as stated in the metalink note?
Thanks.