I just did the two strand twists and went to a meeting for a few hours and I had mixed results. The front half of my hair looked great! No frizz, some semblance of organization to my curls & the ends didn't look as fried. The back half didn't really take to it too much. I think because the back has much tighter curls, the twists really only held towards the bottom portion of the strands but the top just looked like a brillo pad lol.
As far as sealants, I'm new to this so I didn't really know there was such a thing. I just put in the cantu shea butter cream when my hair is wet & that's pretty much it. I don't know how I feel about cutting off the damaged ends only because I'm obsessed with length & I know that I'm never going to be a full time curly girl so I feel like I will always have some damage. I'm sure it would probably look better though.