no. it realy needs to be a prolonged period of time and multiple times.
most people mess with the light hours untill the plant show's signs of hermaphrodism.
i have no idea how long it would take to turn a plant hermi, genetics have a lot to do with it, bad genetics will lead to more hermi's in the grow room, others with top notch genetics may take much punishment to get them to turn.
then there are other top genetics that have a penchant to turn hermi, GG4 GORILLA GLUE 4 started life as a hermaphrodite plant, it was then manipulated into the wonderfull plant it is today, it may still have a tendancy to herm quite easily, i don't realy know.
others may be able to help you with info,
you could use the search engine and look in the breeding forum, theres bound to be info on how to do it, i don't think i've ever read anything about exactly just how long it would take, as i said, most breeders wanting to herm a plant, will mess with the lights and mess with it's enviroment untill it shows sign's of hermaphrodism.
sorry i cant be of more help.
just get a timer, its well worth the money for peace of mind