I don't want to hide the fact that I have had only negative experiences with this method. I've had a fungus in all bottles soon. But according to many gardeners it IS feasible to get at least some bottles without any fungi. Feel free to tell me your experiences.
Store the bottles in a dark place with room temperature, not more than 23 degrees Celsius.
After two months the young orchids will be visible as white specks of about one mm size. Now it's time to prepare a new set of bottles and to transplant the seeds to another medium.