the issue isn't "pulsing", (how often you do this and how long is completely open to interpretation) but like cycco, as someone who has done a lot of loaded big downhill descents, I have always found it better to let the bike run, then do good hard braking applications (using front stronger) to bring speed down very quickly (quickly as in a relatively short braking application) --then letting bike run again with no braking to let heat dissapate.
this always keeps rim or rotor temps down
sure, hairpins and whatnot sometimes/often mean more frequent braking, and the odd really technical, windy, hairpinny descent can mean heated up brakes, but by doing really hard and short braking action, generally means less heat buildup overall---and I've learned this from making the opposite mistake, both in cars and on two wheeled things.
and everyyyyytme this topic comes up, we get to the fine detail that looooooooooots of people don't use their front brake properly, and are "front brake scared", so they don't use it hard enough and therefore have less braking effect with the same amount of actual braking time--which leads to more braking needed, more heat buildup etc etc etc
but interwebs blah blah is never going to teach front brake scared folks how to brake properly, and those who think they are braking properly just dont understand using the front brake really hard--or they think they do, but they really arent., well, not to the most effective use of them anyway.
good old interwebby arguments, gotta love em