I wear my hair in a twistie knot too, but I do use Paul Mitchells Super Skinny Serum in my hair and that keeps it a bit silkier and easier to comb out later. Similar products are Frizeeze serum (not the spray) and Sallys Beuty Supply Genric copy of the Paul Mitchell serum. This stuff is great for after you wash your hair too. You just put a dime size ammount into towel dried hair and then blow dry. It protects your hair and leaves it soft.
Good Luck!