Waves/curls from cornrows?

I have AA hair (which is somewhat easy to manage because I have part indian hair) and it's completely natural, No perm, normally I cornrow it at night and uncornrow it in the morning and when I take it out it usually have nice bouncy curls/ waves which sadly Last like 1 hour or so =< so I was wondering how can I make these curls last the whole day using extra hold hairspray or something like that..... I was wondering if I sprayed it at night after I did my cornrows that they would hold through out the next day after they had been unbraided ? also does extra hold hairspray even work on AA hair? HELP please and thanks