What I did now is I started the 3th seed of the batch I bought, since this one is obviously not going to give me anything. I want to keep it safe on the 1 I still have so I don't want to start experimenting. but if I collect the pollen, could I use it on the one I'm now starting? I just want to make sure I have 1 good harvest at least...
Sure. Protect your sensi crop first.
Males are like females in that they flower for weeks.
If you keep him indoors, for example, just trim away larger flower clusters, and he'll keep putting out more.
You can also store pollen in the freezer to keep it viable. Just make sure it's just the pollen, not the pollen sacks, and that it's dry.
Then can thaw it out and dust your new plant in ... 4-5 weeks from now.
Though, dusting it
on one lower branch only of the present lady would work.
Take it inside, out of the wind, use a q-tip or little paint brush to brush the pistils of the lower branch.
Then cover that branch with a plastic bag for a couple of days.
By then the pollen will be no longer viable, and so won't seed the rest of the plant.
May be a little tricky if you haven't done it before, and understand your situation.
If you're going down the pollination route, please do some reading online.
There's lots of good info, and like anything, best to be prepared, and do it well.