what you are talking about is pretty much what im doing at the moment. i fast for 3-5 days, do a SWF.. then i eat a small meal, fast a couple more days, have some soup for a couple days..etc. reason im doing it this way is because im working up my discipline for an extended fast(im thinking 14-21 days, just water, and perhaps a glass of juice ocassionally). im also young, and also quite heavy. 29 male, 6'1" .. 310 pounds. i have a large frame, and plenty of muscle, so im aiming for about 220-240 eventually, as far as weight loss. of course i realize fasting alone isnt going to make that happen, but it'll be a nice jumpstart to a better diet. then just add a dash of "exercise exercise exercise", and i'll be good to go. hehe
hope it goes well for you. it's not very hard fasting for 3-5 days at a time, and hopefully you can go for an extended fast and really give yourself the benefit of a thorough cleansing. you can do it!

peace