>>does anyone know if it is possible to get a clean break order agreed by the court if one of the parties is not providing any finanacial details?
Yes, if you make an application to the court to determine the financial issues arising from the marriage then the court will ultimately decide whether the other spouse provides financial disclosure or not. Having said that, if one spouse is not providing financial disclosure the court will give that spouse every opportunity to do so and may well threaten sanctions if she does not. That type of behaviour invariably makes what are already lengthy proceedings into something even longer and more costly.
In the circumstances you describe possibly a more productive way forward (assuming you are happy with her proposals for settlement and that they are broadly fair) is to get your wife to complete the much more limited form of disclosure required by a Form D81. A court will not approve any terms of settlement and turn them into a court order unless the proposed draft order is also accompanied by this form. It should therefore be possible to explain to your wife that if she wants you to buy out her share of the house then completing this form is a necessary part of that process. The Form D81 is a relatively modest document which should not take anyone very long to complete. Showing it to her and explaining why it is necessary to get the settlement formally approved by a court would probably get the desired outcome (although some patience might be required).