Oil and butter should eventually be absorbed by hair. I use a lot of really rich products (in minute amounts) on my low porosity hair. I started using natural soap bars to cleanse when they were popular about four years ago. I felt that they were just enough to remove any residual product from my hair.
3a (Corkicelli), highlighted, fine, low porosity

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me, Aloe Fix