Hair porosity test. An opinion on this?

How accurate is the hair porosity test? My hair is extremely dry and gets very frizzy after wash if I don't use conditioner. All of my hair characteristics point towards high porosity. I have been oiling my hair quite regularly since many years however my hair is still dull and lifeless and nothing actually works. What usually happens with people is that their hair gets greasy in a few days after wash which is when they wash again. However, in my case it gets very dry few days after wash which i think is because the conditioner rubs off and then I oil my hair, wash and condition it. So all this should mean that I have high porosity hair. However, according the water test for hair porosity my hair is low porosity. Do you have an opinion on this?