I agree that if she is already prone to unforced hermaphrodism, she isn't a great choice for femming.

-But-

As far as stressing a genetically sound female to make the femmed seeds, I continue this practice with great results, and read my lips..."no strain degredation" Hermaphrodism is a survival trait found in each and every strain, and those that haven't been able to do so successfully, and likely haven't even tried...well those are the ones that often bash the idea of purposefully turning a female. Oh well...their loss...

Gibberellins and heavy metals are often used, but personally...I'm leery about saturating my smokables with these industrial strength hormones and heavy metals.

In my experience, by the time you find the pollen sacks when overripening, your entire growspace has been contaminated, and every female will reap the rewards. (seeds) The sacks usually start forming inside the buds themselves making them a bitch to find and remove. I'm guessing that breeders have a seperate room or building for this.

I prefer to start the femming process at the beginning of the flower stage, with light poisoning or uncoated aspirin. (salicylic acid) both take a couple of weeks to start seeing results. With the light poisoned lady, you can re-veg her back to her normal, healthy self. Using the aspirin though, you can't re-veg the lady back to being a mom. (the crystalline acid doesn't flush from the soil well, so can be a problem later-on down the line)

When harvesting the pollen, I turn off all fans, and carefully pluck the pollen sacks off the plant while holding a small cup underneath to catch whatever falls. (pollen and pollen sacks) The I remove her from the room and hack her back for re-vegging, where she'll revert back to her bad-assed self.

Have you thought of re-vegging her for clones?

Also, likely not a good idea to breed with your femmed seeds. Genetic anomalys can pop-up if you push 'em too far for too long.