I'd rather not use the in-game clock, I messed up one time using it because accidentally pressed to start up the game instead of change the time. I was really tired so that was the problem. It's much better in my opinion to do the 3ds clock, but it's all in preference really. I just finished plot resetting Cousteau and used the 3ds clock. It took 2 days for me to place him exactly into the spot next to Elvis.
After getting the plot to show up and everything, just plot reset like normal until whenever you're too frustrated and tired to reset lol. As long as it's not 6:00am yet, you should be fine. When you do want to quit resetting, TT back to any time after 6:00am, so 6:01am and after is fine. I didn't really care about that since I don't like changing the minutes. Whatever minutes it is at the moment I just adjust to that like if it's :00, then I'd do 7:00am instead of 6:00am, just so the game doesn't try and save, plus I'm too lazy to change 3 numbers instead of 1 lol
When I plot reset Cousteau, the first day I TT time Wednesday to make his plot show up, I was basically frozen for a while.
I kept resetting until I think roughly 1:36am (actual time; 11/24) and then I quit, turned back time to 6:36am (in-game time; Wednesday) and went to sleep since I had classes in the morning. I woke up at 6:45am and the game was 11:45pm. I reset a few times before classes. Then came home and kept resetting again, until at around 2:40pm actual time and the in-game time was 7:40pm was when Cousteau finally decided to put his butt in the right spot.
So that's how I did it. If he had not placed his plot in the perfect spot, I would have just continued and then turned back time again to after 6am when it became too late again, so that's basically how I did it
There might be other ways, but that's how I learned it and that's my fail proof plan and so now my town has all my dreamies in the right place!
Congrats on getting Francine and good luck