As someone who has eczema on their scalp, frequent washes are a must. I wash every 3-4 days and wear it in a high puff to keep the hair stretched. 
My hair has not experienced any mushiness, and it's starting to reach the lengths I had as a child before the relaxers which was about BSB length. Conversely, when I had relaxers and got my hair washed every other week, my hair struggle to get to shoulder length, often breaking off and causing me to get a big cut every other year.The scalp eczema caused a lot of buildup and itching which caused scalp scratches (which made touch-ups oh so painful). My scalp needs to be cleared frequently (no less than once a week) otherwise my hair won't flourish.
Due to my experiences I think her theory has merits, but as others in this thread have said, it's nothing new or groundbreaking...
				
			My hair has not experienced any mushiness, and it's starting to reach the lengths I had as a child before the relaxers which was about BSB length. Conversely, when I had relaxers and got my hair washed every other week, my hair struggle to get to shoulder length, often breaking off and causing me to get a big cut every other year.The scalp eczema caused a lot of buildup and itching which caused scalp scratches (which made touch-ups oh so painful). My scalp needs to be cleared frequently (no less than once a week) otherwise my hair won't flourish.
Due to my experiences I think her theory has merits, but as others in this thread have said, it's nothing new or groundbreaking...
					
				
 If you're looking at the vid in the OP, I guess I could see why you might think that but that's her hair after a massive set-back, bleach-related... it was nasty. 
. Every 3-4 days I would cowash, set my hair in 12-16 twists, let them dry, then set the twistout in 3 braids. I did hot oil treatments with CO every week and clipped my hair up. I was super gentle with my hair, and oiled my ends every night before putting it in the 3 braids. My hair looked great and I had the most length retention ever!! That was what finally got me to MBL 
. Hmmm. . . Maybe I should go back to that 
!!! LOL!! She only washes her hair once a week.
		
 I modified it, mostly out of laziness, but also cuz I'm not a big fan of bs. My step 1 is shampoo. I do everything else according to the method though. 
.  She could have done a better job on her own in her bathroom for $4.95.