The one true answer is it depends. On the flogger, on the person using it, on your mindset, if you’re restrained, etc.
I use a big, heavy, thuddy flogger, and alterate it with belts, crops, a sharp mini flogger, etc.
After a nice gradual warm up, I increase the intensity. Veronica says that she starts to float, and about a half our in, she’s taking some very hard strikes with no problems.
The keys are a good warmup, and constant communication with your Master