This is the least expensive and most privacy conscious way to produce fem seed.
Simply construct a generator using a 9-12v power supply (DC output, if it says AC then its no good) that can deliver at least 250ma (most wall wart type power supplies work, batteries are not recommended since their output varies over time). The supply will have a positive and negative lead, attach silver to each lead (contrary to internet rumors, you aren't drinking this is cheap 925 silver is more than pure enough) you can expose the leads by cliping off the round plug at the end and splitting the wires, one will be positive and the other negative just like any old battery. Submerge both leads about 2-3 inchs apart in a glass of distilled water (roughly 8oz). Let this run for 8-24hrs (until the liquid reads 12-15ppm) and when you return the liquid will be a purple or silver hue and there may be some precipitate on the bottom.
This liquid is called colloidal silver. It is nothing more or less than fine particles of silver suspended in water so it is a completely natural solution and is safe to handle without any special precautions. The silver inhibits female flowering hormones in cannabis and so the result is that male flowering hormone dominates and male flowers are produced.
To use the silver, spray on a plant or branch every three days prior to switching the lights to 12/12 and continue spraying until you see the first male flowers. Repeated applications after the first flowers appear may result in more male flowers and therefore more pollen. As the plant matures it will produce pollen that can be collected and used to pollinate any female flower