Is it too late to make feminized pollen?

I have a female autoflower that is a cross of a friends (White dwarf x double grape) x Strawberry nuggets and an lsd auto I grew myself...the f1 female I have now is really nice and strong has nice big thick buds and is covered in sugar and the smell is like grape bubble gum. I really want to make some fem pollen with it for later use on another strong female but its in the 5th week of flower and will be ready to harvest (as far as potency is concerned in a couple weeks id say. My question is...can I still use colloidal silver on a branch and have time for the sacs to grow and produce pollen even tho its so late into flower? I am not terribly concerned whether or not I loose most of the bud or not. Although my plan was to harvest most of the bud a lil early and leave a branch or two in tact and spray those couple branches immediately. Thanks in advance for any helpful advice.

Another question i have is how do you selectively breed autoflowers for potency when you can't flower a clone to see what she's gonna put out?

You need to start spraying prior to the plant flowering. You can try it on a branch but if you do manage to get some pollen sacs to grow chances of getting viable pollen are slim.

Thank you and you were correct btw. planning to give it another try on the next grow. Any tips on getting it to work would be greatly appreciated.