@Kaktus. Don't give up on hand pollination. The reason for failure can be many things. Maybe the plant is not receptive at the time, two or three days from opening usually works. Maybe the pollen is too old, it should be almost granular but slightly sticky. Maybe the pollen was not applied to the proper part of the stigma (the main reason for failure).
Possibly small insects have eaten the pollen and stigmatic surface after the pollination. I once took a flower that I accidentally knocked off a plant and opened it to get the pollen only to find tiny worms crawling in the pollen.
These pics may be helpful.
Standard flower
Flower with two petals and corresponding tube removed. The fuzzy pink parts are the anther tails and serve no purpose in hand pollination. (Interesting side note, in some multi-petaled plants these have developed into petals so when you open the flower they will be missing). The fuzzy white cone with the slits in it contains and protects the pollen and the stigma. The pollinators take pollen from the top slits and deposit it into the bottom ones.
In this picture I have removed three of the anther tails down to the top of the stigma (which is not receptive so any pollen that falls on it doesn't pollinate the plant, nature's way of forcing outcrossing). The toothpick is touching the area that has the pollen, the top half of the fuzzy white cone.
In this pic you can see that the pollen is brown and crumbly looking, probably no longer viable. It should be greenish yellow to straw brown in color. The toothpick points to the area that houses the receptive portion of the stigma.
Here I have pushed the toothpick through one slit and out another. This is where our friendly bees put the pollen.
Here I have removed a section of the cone to expose the stigma (the shiny part) and the tube leading down to the ovary
The toothpick is pointing to the receptive part of the stigma, the bottom side not the top. Imagine our little insect looking for nectar puts it's face or feet or proboscis into the closest slit to the flower face and finds none. Not to be deterred our intrepid creature, now sullied with pollen pushes on to the deeper slit and when it leaves/backs out it pulls its appendages back through the deeper slit thereby depositing pollen on the underside of the stigma and, assuming the plants are compatible, pollination has been accomplished. Kaktus, be the bee!
