I've been doing intermittent fasting quite regularly for the past year or so. Often will do a 24-36 hr water fast (have done a 72hr water fast once) and have done a 48hr dry fast too.
From my experience - haven't found a better way to accelerate natural body healing/advancement of health in general and detox than that.. :)
Especially powerful for emotional debris cleanup.. as all things come along to the light for it to be dealt with. However, it's important to listen to your body.. I never do it if it doesn't feel right.