1個月!? (I think nowadays is not work anymore!),我係醫院忍左3日, 沒有洗頭, 但有用dry shampoo. I have read a post abt that b4: 長輩以前係用井水-比較涼, 加上當時又無咁多野進補, 又無風筒/暖風機...咪話唔好濕水law. 但現在我地咁幸福, 沖涼洗頭後, 即刻9秒9乾身吹頭(一定要全乾)便可以,但都一定要穿長袖衫褲, 以防冷親, 室溫最好keep住25度, 入風係會變風濕, 風濕痛係好辛苦ga, 忍到咪忍下啦, FYI, I use the ginger shampoo to wash hair for 3months. Hope can help you la ;)