I have this old bed, and I am in the process of stripping it to get the old finish off it to re-stain it and make it look new again.

Here is the bed before start of this project:





And pics taken just a bit ago, showing my progress:





So, for those of you out there that know about this stuff, or have experience, how do I go about getting the residue of white paint or primer that seems to be stuck in the grain?