in reply to XML:twig XML wrong

You can also use XML::XSH2's stream command that doesn't load the whole document into memory. 
stream :f input.xml
       :F output.xml
       select (dobs | dob) {
           rm ../* ;
       }

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map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In Section Seekers of Perl Wisdom