It's well worth getting your head around the advanced search function, there are various threads on the benefits of coconut oil and how people use it particularly on the DIY/ natural board. Also some great articles on oils and butters including one specifically dedicated to coconut oil on the main NC site by 'curl chemist' Tonya McKay, the Natural Haven blog is also well worth reading.
You can't rinse coconut oil out because it's an oil so not water soluble, you would need to CO-wash or shampoo out the excess. Some use it as a pre-wash, some as an intensive treatment, some in small doses as a leave in sealer.
There is no benefit to worrying about hair, you will only affect your health which in turn affects your hair. Build up can always be cleansed away with ease, the only way you can know how your hair will respond is to experiment.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.