Flip both, then when you see flowers spray one every day for 14 days (this is for CS), this way when you have pollen you also have ready and waiting female flowers to get prego. Seeds on the pollen donor will be S1 feminized, and the others are F1s feminized, if this is your own cross. S1s can be more subject to hermie.
Edit, never spray and leave the lights on, your girls will get burned.