First, I just posted in the thread "Incivek weight gain and rash" responding to your post in that thread so please go there and read it.
As far as laundry soap, I use a biodegradable, hypoallergenic laundry soap that I get at my local Food Co-op (healthy food store). It works fine and I have never had any problems with it.
My mom always had to buy a really cheap detergent because EVERYTHING else made me break out. It was powder and didn't work really well. Tide free is what I use now and aside from a rash just from the change, I haven't had any issues with it. I also found out some of my clothes are white!! I assume most of the dye and perfume free ones would be ok. If all else fails you can try plain old borax. 20 mule team(?) is a good one.
I'm thinking we're going to have to look into some kind of free and clear detergent also. Not sure if what we use know might be causing at least some of this rash, but it's worth a try to try something different if it might help.
when i was starting tx i was using costco ecos. i had the WORST rash on my trunk. it was horrible. i was miserable. i went back to all free and clear and i've been fine. the ecos has coconut oils in it. my doctor said i may be allergic to that. after tx i'm going to an allergist to find out. good luck. belle