All great advice! And I can say they all work, for I've tried I think every thing mentioned here so far. (LOVE Henna and Placenta! LOVE Henna, period!)
I've also used mayonnaise in a conditioning pinch (it contains both the egg yokes and oil, which as others have mentioned are great at home remedies...) I usually wrap my hair with a few good long pulls of tin foil too when I deep condition my hair, and then a towel maybe that's been in the dryer for a bit to warm it up nice? Seems to hold the heat in well. I've also held a blow drier to my foil wrapped tresses before too for the same heating purposes...
I used to have a roommate that regularly conditoned her hair before going to bed with either mayo or olive oil and she'd just wrap it up and let it penitrate all night, then just wash it out in the morning... She never had a problem with it being too greasy feeling, and in fact she had beautiful hair... (too bad she was a pain in the ass though and I had to kick her out... She used to "steal" and use all my beauty products - uh, like the mayo and olive oil and my shampoo among other things!)
I also read online recently of various different models who keep olive oil in their hair for DAYS on end before a shoot to keep it looking so nice apparently..........
Good luck!