Nasal Air Guard

Has anyone tried the nasal air guards to help with hayfever symptoms and if so have they been helpful?

My consultant recommended them today as I'm on maximum meds but still having some symptoms and I'm willing to try them, but they're quite expensive (particularly once you work out the cost for the whole hayfever season) and I'm not sure I can justify that cost as a student - but on the other hand, if they work, the relief might outweigh the cost disadvantage.

Here's the website:

nasalairguard.com