Is there anything else i can do to get rid of my cats fleas?

My indoor cat has fleas, Ive put the spot-on on his neck, sprayed him with flea spray, i brought a flea comb and try to brush out as many fleas as i can twice a day, I wash all his bedding and other bits he sleeps/ lays on on a hot wash and ive been hoovering like a madden! I even gave him a bath much to his dismay, tonight i brushed out around 15 fleas, Is there anything else i can do to get rid of them? and how long does it usually take before they are all gone??