There isn’t a “set” time, but there is a minimum time that it takes the body to rebuild damaged cells.
And if your cells are damaged, would it not make sense that your unit would tell you to take it easy for a while?
If you tried to work out the same muscles every day at the gym, your body would tell you to take it easy. If your dick feels fine and you are making gains, I don’t rest days are a necessity.
That being said, my entire routine consists of erect jelqs and I probably do about 160 or so a day, nowhere near the amount that RTG does.
I guess we could all agree that it depends on the person and the routine.
Starting size: 7"x5.25" bp
Current size: 7.25"x5.875" bp
Goal size: 8.75"x6" bp