My baby also has rash and my doctor told me not to use those expensive BABY stuff for bathing. Just use clean water to wash babies with soap like LUX is OK.
My doctor recommend me to buy "Sativa" 匡膚健 - 燕麥淋浴軟膏 (HK$120 for 600ml) & I have used for about one month, I think it is quite good for my son.
My BB also drink A+.