Pollination of mammillarias

[juste.dcv]

Hi
So yesterday I walked into the store and found the whole tray of mammillarias in bloom. I decided to buy 4 of them just to try pollinating them. I've never done that but I love sowing cacti so it would be even more exciting to sow the seeds from my own garden I took a small brush and pollinated each cactus with the pollen from another one (I am not sure if this is how it's called in English, but I am sure you understand what I mean). Is there anything else I should do for the successful pollination?
Thanks in advance

[Aiko]

I would advise to repeat the process, until the flowers have wilted. There is no guarantee they will be pollinated after just one try. Age of flowers could make a difference.

[juste.dcv]

I would advise to repeat the process, until the flowers have wilted. There is no guarantee they will be pollinated after just one try. Age of flowers could make a difference.

Thank you, I will definitely do that!