Not a Brain, but I would think it would depend on what ingredients the pomades have in them. If they have silicones you would most likely need to use a shampoo with sulfates periodically to remove any buildup. Maybe the Brains will post about this.
As usual, LindyGirls rocked the house. The removability of any given pomade TOTALLY depends on the ingredients in that particular formula. If it's a light polymer based formula, SLS-free is probably fine. If it's a very heavy silicone or wax intensive formula, you may need the extra cleansing boost you get from SLS. Of course, you could always lather, rinse, repeat...