Congrats on contributing to the core!

If others want to use this in their own Perl programs now, they could use Inline:

use Inline C => <<EOF;
int curse( SV *obj )
{
  if (SvOBJECT(SvRV(obj))) {
    SvOBJECT_off(SvRV(obj));
    SvSTASH(SvRV(obj)) = NULL;
    return 1;
  }
  return 0;
}
EOF

my $a = bless {}, 'A';
print ref($a), "\n";
curse($a);
print ref($a), "\n";
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update: added clarification and congrats