Hotkeys are a great alternative for starting and stopping the dictation without using the mouse.
There are a couple of alternatives for starting and stopping dictation that do not involve clicking the mouse.
Talkatoo has hotkeys, or a sequence of key presses, that will start and stop dictation for you. These are currently not programmable, meaning that they cannot be changed, but this option will be available in a future release.
Press all 3 keys together and release to toggle the dictation on and off.
You can also show and hide the Talkatoo toolbar:
An even better alternative is to use a premium handheld microphone with programmable buttons, such as the Philips SpeechMike series. This microphone come with software for programming hot keys. In addition to starting and stopping dictation, it can be configured to press Tab, Enter, or any other useful key or sequence of keys, as well having a built in mouse with buttons.