Well sure. In nature the tomato plants self pollinate by wind blowing and shaking the plant causing the pollen to drop and fertilize itself. In the green house there is no wind so the toothbrush vibrates the flowers causing it to drop pollen and fertilize itself. Hope this answers your question.
Derek, you are quite right and it is a problem that I have not figured out yet. I have to have a 40% shade over my green house to help with the heat. It is May and the temp already reaches 95 degrees inside with the fan going. If you have any suggestions I am always looking for a solution other than a green house chiller.
Update: I wish I could add a picture but I took my the last 3 grommet holes on the back corner of my shard and ran 1 bungee cord through it and pulled it toward the front of the greenhouse to give the tomatoes more light.
