Whenever I am on the road for more than a few days, I sink wash to help me travel light. For a long time, I used the little travel sized individual packets of Woolite for my sink washing, but those little packets do need to be in the 3-1-1 baggie. (Yes, I know you can probably get away with not putting them in there. But if you get a mean/stickler/having a bad day TSO...well, you know the drill.)
I switched to Forever New recently--it is designed for lingerie and comes in a powder. I use it at home for my 'fine washables' and also for my pillow cases. I started to carry a small screw-top container of it while traveling--since it isn't a liquid it doesn't need to be in the liquids and gels baggie. And although it cleans well, it doesn't suds excessively, so it makes rinsing easy. But honestly, it was a bit of a pain in the neck compared to the ease of the 'squeeze it in and discard the packet' Woolite packets. Sometimes I got a bit of water into the jar and the remainder clumped, it was hard to judge the right amount per sink-wash, and sometimes I ended up bringing too little for the trip. So it wasn't a perfect substitute for the convenient (but pretty expensive on a per-use basis) Woolite packets.
Recently I saw that Forever New now sells its product in little packets, too. I was about to pull the trigger and buy when it occurred to me that I could make my own packets up if I spooned the right amount of product into those little zip-lock pill baggies. (If you don't know about them, they're small plastic ziplock bags that are about two inches by two and a half inches--perfect for ten or twenty pills. I always use a few for aleves, immodium, etc. in my travel tray. As I recall they come in packs of 100 for about 3 or 4 bucks. Because they're reusable, I'll probably never have to buy them again!) Now, for a small fraction of the price of buying the made-up packets, I can have my own to take with me, all set with exactly the right amount for a sink wash.