Bagseed can go either way. It could be from a hermaphrodite that grew balls and didn't get noticed where the seeds will not be feminized. It could come from pollen formed in nanners hidden in the flowers in which case the seeds will most likely be feminized. Some use the term rodelization for nanners that form late flower and it is an old method of making feminized seed. It's not reliable which is why chemically induced reversal is the primary method used. STS, CS, and some still use Ga3 are the only viable way to successfully produce feminized seed at any level of scale.
I prefer using STS. It's proven to cause a female plant to produce male flower parts that develop pollen that carries only the female chromosome and is highly reliable and is likely the most widely used method by breeders around the world at this time. CS is highly reliable as well granted you have a good source of CS. Unfortunately many buy premade solutions online and in many cases those solutions do not produce the desired effect and an individual is just spraying without ever achieving the desired goal. Producing your own CS which is a simple task or mixing your own STS are the preferred methods used by those that are seeking the most successful results.
Back to bagseed. The only way to know is to grow it out. Keep an eye on it and see what develops. When in doubt, grow it out.
