If you have a successful pollination you should see seeds starting to form within a week. The base of the pistils will start swelling. It's hard to explain but once you've seen it it's unmistakable. Within a couple weeks they'll have grown but still be green then they finish off over the course of the next 2-3 week. Seeds take 4-6 weeks to mature. Some a little longer. If you only found one premature seed in the bud 7+ weeks after the fact then the pollen didn't take and that seed was likely a dud.
With a good pollination you'll have buds loaded with seeds.
CS works. Many people use it and I have used it in the past myself. STS is a more reliable method which requires less spraying and is the preferred choice for most these days.
With an optimal reversal the plant will flower like a male without any female inflorescences. The pollen will fall out on it's own and can be collected over a plate or tray.
This was a female plant reversed with STS. Fully reversed with pollen falling out on it's own.
You should have no trouble identifying a successful pollination.
It's too bad the process wasn't successful for you this time.
A couple tips for your next effort.
Wait for the pollen sacs to really start opening and you can collect it. Sometimes the first sacs to open don't produce viable pollen.
Be liberal with the pollen and do 2 pollinations a week apart.
Think about switching to STS instead of CS.
Start spraying before the plant starts flowering.
so ,not optimal