Fingers crossed. At least you'll be able to check for line noise as the filter will exclude the broadband signal to the phone.
If there is still noise on the line then an engineer is still needed to resolve.
As an aside I've just checked and I have 7 new filters and 10 1mtr ethernet patch cables I've been sent over the years.
I've given away a few over the years too to those who have needed one.
Am I the only one who hangs on to these things "just in case"?