I never used products or did treatments before I started lurking on nc.com almost six years ago. When I started, my hair was winter wavy/summer 3a. The things I learned here have strengthened my curl pattern. My hair now looks like my signature picture every day, all year around. I don't look for products that provide hold, my hair doesn't seem to need much.
I wet, use a rinse out and style every day. Don't try for second day hair, so I can't really answer that question.
What I would say to your science brain is that the correct balance between moisture and protein will optimize your curl.
3a (Corkicelli), highlighted, fine, low porosity
modified CG, since April '07
CG since 3/11/08
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