I don't agree with "Sanding again only gets you back to where you started.".
The reason for whiskering is that any time wood is removed, whether by scraping or sanding some of the fibers will be uncovered and they will be free to move.
If subjected to a fluid like water most of them will continue to lay where they are but a few will suddenly say, "I'm FREE" and they will stand up proudly.
These are the whiskers and we want them removed so they don't continue their behavior when the stains, aqua-fortis or finishing oils are applied.
While the surface is still wet or damp, not much can be done so the wood must be allowed to dry.
Once dry, the whiskers hardness will hold it firmly in position.
Because these non conformists were part of the grain they will be pointing pretty much in one direction. To discover this direction (it is important), rub the back of your hand on the surface parallel with the wood grain.
In one direction it will feel pretty smooth.
In the other direction it will feel like a bristle brush. Remember this bristle brush direction.
With the whiskers fully dry I prefer to use a piece of brand new 220 grit sandpaper to remove them. Used sandpaper will just crush them back down so they can pop up later.
Using almost no pressure, I very lightly stroke the sandpaper in the bristle brush direction.
This will cut off all of the standing whiskers without exposing any new wood fibers on the woods surface.
Very little "sandpaper dust" will be seen on the paper because only the proud (and now removed) whiskers are cut off.
It only takes a very few strokes of new sandpaper to completely "whisker" the surfaces of a stock.
As for water darkening the curl's stripes, all that is being seen is the dark "end grain" of the curl.
This end grain is why the stripes are visible and look different than the adjacent areas of the surface.
Just let the water dry out and the contrast will return to the pre-wetted look.