"Unconfigure" oracle database

I have an Oracle 11g RAC installation which I want to "unconfigure". This is a cloned machine which has an Oracle 11g RAC installation. I want to "reset" it (drop databases, configuration etc and keep only the binaries) so that I can re-configure it according to my new requirements. Oracle provides instructions on how to Unconfigure Oracle Clusterware without removing binaries , which as far as I understand refers only to the CRS (and I am not sure it applies to 11g). However I want the same procedure for the database too. Is there anything similar? Regards