I've heard shampoo with Salicylic acid does wonders but haven't tried it yet. What has helped me so far, is using a good amount of hair conditioner or combination of oils (castor oil with few drops of tea tree oil along either other one - I've mixed them myself ) as a mask, leave it soak in and then I comb my hair thoroughly. It encourages the flakes to go off and keeps my scalp moisterized. I do wash my hair afterwards with a shampoo that has only 2% soap, that is prescribed and seen a big difference.
Also when my patches go bad I use my prescribed gel as a mask leaving it on all night... Most them are eased off in the morning. Hope all this might help!