High rep cleans are defenitly hard to do. Here are some things I have aagainst this though (not that it is a bad idea):
1) The "clean" is a power exercise. The whole point about it is to be able to toss around some serious weight for doubles or triples. It is a full body exercise and very taxing but in my opinion I feel like it is an exercise, like deadlifts, that lends itself better to lower reps
2) I owldn't recommend doing this at the end of your workout, like you would most cardio (ie bike, elptical, etc) because it is such a demanding exericse on the central nervous system. The force output is so great as well and if you are fatigued there is a danfer of over exerting yourself and possibly pulling a hammie. Now, you could try doing it on an off day but again the trashing the CNS takes would seem like it is to much.
3) You are still lifting weight, even though the intensity is low, which still places pressure on the thoracic cavity and impedes the proper function of the left atria and ventricle, because blood can't get nack to the heart and out to the body as efficeintly with this pressure on the cavity. Which is something that you don't get when you do regular cardio, or even HIIT sprints for that matter.
Just my opinions.