These specifically state "no additives", but definitely not dollar store prices.
http://www.magellans.com/store/Health___Hygiene___ToiletriesTA899?Args=I actually bought the "disposable underwear" from these guys, came in a 5-pack, took up about 6 inches(?) in my luggage, threw them away as they became raggedy, wearing them several times before they gave out.
I also buy their shampoo/conditioner/soap/laundry soap sheets. You can carry them on because no liquid, although you have to use more sheets per "wash" than they recommend.