i jsut read through my reply and it doesnt make sense.
people bath dogs because they get dirty and don't clean themselves suffiently in our opinions so we barth them. but cats keep themselves cleaner so humans don't feel the need to clean them but if it is getting dirty, bath it.
Yes, I think you can get special shampoos at the Vets. Possibly better to use one because it won't affect his skin. You may need leather gauntlets and a protective face mask!!! ;o). I would bath him in the kitchen sink where you have more control on holding him than a bath. Use luke warm water. He will look totally stupid when he is all wet and may well go right off you and sulk for a good few days.
mmmm, my wife has given our cat ' Tommy' the occasional rub down with a fairly damp cloth ( with me holding him ) no special shampoo used. I suppose how your cat reacts is down to his temperament.