I have alot of red oak trim throughout our house that is now 15 years old.  We originally sealed the natural oak with 2 coats of regular oil based poly.  I have been noticing that there are alot of areas where our hands must have left a buildup of dirt in the tiny ridges and pores of the grain, mostly around edges where we must hold on to the wood.  I tried cleaning it out with windex, then with an oxy/water mixture.  There are still dark lines in the grain which I assume is still grease and grime.  The oxy/water solution actually took off alot of the old finish around the edges. Now I wonder if these areas will blend when I recoat the entire piece.   

Since we are putting everything back together after a major remodel, I would like this wood to look good again and am not sure how to approach this task.  Also the overall appearance of the wood has a very amber appearance which I know is what oil based poly does but it has a tired appearance.  How can I clean the dirty spots, and recoat to bring back its good looks.  I do not want to strip it or sand down to raw wood.  Is this possible.  Any insight will help.  BTW– I purchase Formbys “Build-up Remover” and 0000 steel wool yesterday but have not tried it.  thanx