I don't think it is a waste of time and money, but you will probably get the best results from longer exposure times or by applying heat (heat cap, blow dryer, shower cap and towel if you have a warm head) or frequent treatments. You don't need pricey branded/ extra virgin coconut oil either, the studies are using basic refined oil.
One of the studies left the oil overnight because the researchers were aiming to mimic how certain ethnic groups use coconut oil. Another was looking at diffusion into the cortex after twenty four hours, not to say you won't get absorption occurring faster just the research has not been done on shorter time frames.
My gut instinct would be you could get results in two hours especially with some heat because the molecules are small and have an affinity for protein. You can certainly get excellent diffusion of semi permanent dye molecules into hair than endures for weeks or months with a two to four hour treatment. But that is done on dry porous hair and works best with a high pigment product (lots of molecules). The more you dilute the coconut oil the less opportunity there is for lauric acid molecules to diffuse in so maybe do more oil, less honey, less conditioner and be sure the hair is only slightly damp?
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.
CO-wash: Inecto coconut
Treatments: Komaza Matani, coconut oil, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume, Inecto argan
Styler: Umberto Giannini jelly, Boots Essentials gel
Experimenting with: going back to basics