Question about pollen

I only have feminized seeds, and only grow one plant at a time. I am thinking of stressing my plant into becoming a hermaphrodite in order to harvest pollen to store for later use to produce seed stock, and for use in hybridization in other lines (I have 6 strains that I like). I would prefer to go this route, rather than have to expose myself to ordering more seeds.
My question is, how long can pollen be stored effectively? Also, since I am growing only one at a time, I plan to introduce the pollen only to lower branches, so I don't spoil the whole plant. What is the best time to introduce the pollen (minimum time needed for seed maturity)?

Bump I wanna know this one too, i have 2 power skunk females and 2 purple power females and one male purple power, so i can seed too.