I found this at Grow Notes:

"Use pollen sacs from old or fading blooms - they will already be quite dry and the pollen inside should be powdery. Alternately, you can use pollen sacs saved from flowers that bloomed earlier. They are easy to keep for use in future crosses by storing in a paper envelope with a desiccant."

"Desiccants - You can purchase desiccants in various forms from craft stores or any retailer of dried or pressed flower supplies. You can also collect and reuse desiccant packets from shoe and leather goods purchases - they can be reactivated over time by zapping them in the microwave on low heat for 1 minute."

You could use rice as a temporary desiccant if you don't have anything else on hand.

Here is a link that might be useful: Hybridizing African Violets

Thanks Moose ! Very helpful! :)