I am inching a lil past tailbone length with 5 months of new growth poppin. But I cut my wash days back to once every two weeks about 3 months ago, instead of weekly. I felt washing every week was beginning to put too much stress on my hair, given the fact im still trying to recover thickness lost from a postpartum/post-surgical shed a year or so ago.
I apply diluted shampoo to my scalp only (half dollar-sized dollop diluted in an applicator bottle with 8 to 9 ounces equal parts AVJ + water), and heavily condition the ends. I heavily seal the length after using the LCO/S method, and tend to apply an herbal oil to my scalp. Oh and I love an ACV + cool water rinse last after rinsing out my conditioner. Keeps the itchies from coming up a week later. The herbal oil helps this too.
I moisturize several times a week, and always have my hair up. Just a preferred style for me. I guess going more than 1 week is fine if your scalp isnt oily, you dont workout, or perspire much, and your hair isnt breakng due to lack of more frequent protein and moisture. These things apply to me.
Besides, I personally found that even co-washing too much can drastically thin your hair from combing to detangle (even though I use good quality seamless combs, my hair is fine in texture, and doesnt like a whole lotta manipulation). Im not one of those who can wash my hair with or without shampoo and not comb it out afterwards...and I mean a thorough comb out, or Im asking for mats.