Is laxative tea /SWf really necessary? I did MC before w/o either

I was wondering how necessary the laxatives are? I did the Master-Cleanse over the summer for 10 days, and did the SWF (Salt-Water-Flush) once in the middle, in which I had a bad experience. My body retained the salt and I actually experienced bleeding and kidney pain. I imagine it is very hard on your kidneys to absorb that much salt. And I do not want to mess with laxatives, which I know are hard on your body. It just doesn't make sense to me to try to help your body with fasting and then harm it with laxatives. I did the Master-Cleanse like I said w/o this, and I had great results.