Finish/Protect Jarrah External Doors

The paint left in the grain will show, but depending on its colour may not be all that noticeable.

You could try something like a brass bristle brush if you don't want to hit it with paint stripper.

My recommended finish - seeing as you don't want a high gloss - would be an oil finish; one of the decking oils would be an easy way to find something.

No matter what finish you use it will need maintennance - if you go the varnish route you'll be looking at sand and revarnish around every 5 years, which I think is considerably more work than quickly wiping on some fresh oil every 6-12 months.

I'd probably be tempted to use an epoxy resin finish on the top and bottom of the door to seal it well in those 'out of sight, out of mind' areas.

I've hit it with a heat gun, sander, paint stripper (not in that order) and the 3M abrasive pad that you use on a drill and I still have paint in the grain (only slightly) Actually that 3M pad really worked well. Wore a few of those out.

Thanks for the tip about the deck oil...