I'm not sure why density would have you using thick creams and heavy butters. Density is how much hair you have. IMHO, it would influence the techniques you use to insure you distribute product, not what product you use.
The float test is notoriously unreliable. If you question your determination, why don't you do the live curly/live free hair analysis??
3a (Corkicelli), highlighted, fine, low porosity
modified CG, since April '07
CG since 3/11/08
HGs: Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; DM MiraCurls Curling Gelly; UFD Curly Magic; Shescentit LIs; Sevi conditioners; Botanical Spirits Puree, CJ Repair Me