I just got some wipes from a lady who makes them on eBay, they are flannel one side, and rougher on the other side, it's a little like microfibre - not sure what it is but they are fantastic on poos.

I just do a bucket of water with soap and tea tree oil in it, using up all those sample products I picked up when I was pregnant. Then I wring them out, and put them in a lunchbox. I can then either leave it on the change table or take it out with me.