Olive wood smoking pipe ?

Well I am in the process of breaking in my Mr Brog olive wood pipe.
It smokes very well though I must admit I am cautious about Bent pipes as I have had a couple where draw holes clogged up and one in fact proved impossible to clear.
However with this one I am making sure a thicker pipe cleaner passes through without problems.
However the bowl seems to get very hot quite quickly but hopefully as a deposit builds up that may get better.
And before anyone comes back telling me to draw more slowly and not fill the bowl up, I do know how to break in a pipe!
What is concerning though Is the filter.
I always use a 9mm filter on all my pipes, which are mainly Peterson and Savinellis.
The filter always looks good for 2 or3 smokes, though I do replace every smoke.
However with this new Olive wood, even using my regular tobacco (Thomas Radford Sundays Fantasy), and only filling bowl a quarter full, the filter is absolutely filthy and no way could it be used more than once.
The stem seems to remain quite clean so the filter is doing its job, but even so I am surprised it does get really stained so any comments ?