using a leave in as a twisting creme is tough because leave ins are usually light moisturizers so most of them just have ingredients that evaporate when the leave in dries. try using a regular or deep conditioner. if you pick one that has weight properties (e.g., BMS, BC) in the top before emollients and slip ingredients, then your hair should feel moisturized for a while.
i have been doing this method for a little while now and my hair is happy...and i have cut down on the whole LOC thing...i'm still keeping my eyes open though because i have been doing the loc method for a long time and can go back if the conditioner method is not working out, but so far so good.