I did this and I did get an inch when I measured afterward. I've been wanting to try this for a months and finally made myself to do it.
I washed and conditioned my hair beforehand and had my hair in loose twists. I then added the mix of two eggs and 5 tbsp of EVOO (I dropped my bottle of grapeseed oil in the shower the day before). I had a small section of hair that I used for the before and after. I measured beforehand (drew line on my boob). I left the mix on for an hour (watched Being Mary Jane) and washed it out. My hair seemed to be fine with the mix though I did have a knot of 10 strands I had to cut (I just took my hair out of braids and didn't comb through thoroughly). Everything else was fine. I added the coconut oil -- it was soft solid and melted as I added it in my hair. I rubbed it in my hair and massaged my scalp. I put on a couple of show caps, a shopping bag, a scarf and a bonnet.
I did this really late (around 10:30 p.m.) and was kinda tired. I drew the before and after lines on my skin because I did this at the last minute and didn't feel like looking for a shirt to mark on (kinda wish I did). I had to keep remarking my skin after each shower to keep the lines dark.
I also left the coconut oil in my hair for like 15 hours. I was tired today and had to muster up the strength to rinse it out. I also deep conditioned my hair, which is still in and will be for another 8 or so hours when I wake up.
I told my BF that my hair grew an inch overnight and he was like sure, that can't happen.
But it did. I will see if my hair will still hit the 1 inch line after I wash out the deep conditioner and my hair has airdried. Depending on what happens then, I'll try again next month and will document better to share.
I looked at the videos of the girls in the OP but also watched these ladies.
ETA: I checked my hair after it airdried and it still was an inch longer. I will do this monthly along with my other treatments.