I have lots of problems with hives, eczema, and itching. Here are some of things I've found.
A great detox bath is to put in 1 cup ES and 1 cup ACV for every 50 lbs of body weight, though it sounds like it might not be good the day of the flush.
Skin brushing: use a natural bristle brush. Start at the extremeties and work towards the heart. It can increase itching in the short term, but done every other day or so, my eczema will reduce. This is good for those times between flushes
1 tblsp ACV in a cup of water (drink with a straw to protect teeth) will get rid of the itching, hives and swelling I get in my hands and feet.
Baking soda baths help with itching as long as it isn't caused by dryness.