i use open sesame for the first two weeks of flowering and i have had plants show their sex in as little as 3 days...heres my schedule
1st watering in flower 1/4 tsp OS, 1 drop super thrive, per gallon
2nd water (3 days later) 1/4 tsp OS, 1 drop super thrive, 1 tsp tiger bloom
3rd water (when needed) flush
4th water (when needed) 1/4 tsp OS, 1 tsp tiger bloom
5th water (when needed) flush
6th water (when needed) 2 tsp tiger bloom... and then 1/4 tsp Beastie bloomz
the stuff is exspensive but worth it!