This program will automatically press the space bar for you without you having to manually press it.

Download Auto Keyboard[www.murgee.com]

Use the drop-down menu to select "Space" as the key to automate.
Change the "delay between keys" to 1 milli second.
Change "number of keys to automate" to 0 (zero).
Create a shortcut to start/stop key pressing by clicking in the box, pressing your shortcut keys, then clicking 'save shortcut key". I used Ctrl + Shift + S

Your program window should look like this:

1. Open Auto Keyboard and the game.

2. Click "start game", which should bring you to the character selection screen.

3. Pick a character (doesn't matter which), click "that's me", and you should arrive at the language selection where you get to pick what language to say no in.
Rather than replaying chapters, this is the easiest way to say no many times without interruptions.

4. Hover your mouse over any of the languages, then press the shortcut you set up in Auto Keyboard. This should begin the auto pressing of space and your character will be saying no repeatedly.

5. You can then leave your computer and let the no counter add up, but you will have to stay clicked in on the game screen with your mouse hovered over a language.
If you'd like to pause it so you can use your computer for something else, use your Auto Keyboard shortcut to start and stop it.

Steam overlay will not show you the real counter for the achievement progress while you are in game, but exiting the game will allow it to update if you would like to see how many nos you're at.
This progress is saved so you can quit the game and redo these steps at any time to continue, and Steam will automatically track your achievement progress.
Or if you're patient, you could leave it running for a few hours until you see that the achievement has been earned.