You may have already tried an auto clicker and found that Clock Simulator's seconds are not 1000ms(1 second) long. Whether this was done deliberately or not... for me, a perfect second in Clock Simulator is closer to 970 milliseconds and some randomization seems to occur. I assume timings will be different depending on where it runs! Others have reported perfect click timings of 950ms and 930ms.

Well, here is a script I wrote with some trial and error. It eventually got me 15 perfect clicks in a row. I have no doubt that the timings can be improved more.

1. Install AutoHotKey
   
2. Create a *.ahk file and paste this code in.
   
3. Double click the new ahk script to load it in AutoHotKey.
   
4. Press F12 while in game to toggle the script's automated clicking. I used the "Test your skill" level to key-in these timings.
   
5. If the timings in the script do not work for you after some running time, try changing 970 to another number. Save. Double click the script again to re-load. Go back to the game, rinse/repeat. Good luck!