I take the tablets and really crush them up as they don't seem to dissolve well, especially in cold water.
The Spray & wash tablets work great, we used those recently and I will be packing them for the next trip.
If you take softener sheets be sure to pack them in some plastic baggies and not put them in a suitcase with any food items as everything will taste & smell like softener.
I save my quarters in old 35mm film canisters and take a few with us.
I also put the dirty laundry in regular drawstring garbage bags in the room (sorted by whites, darks, etc..) and then they are seperated when I get to the laundry area.
I put the drawstring bags in one of my rolling pullmans and take that down to the laundry room, then fold everything & put it back in there and roll it back when I am done. I put the tablets, softener sheets and quarters in one the pockets so I am all set.
Depending on what your schedule is like, this may or may not work. I usually find that I cannot sleep terrifically while at WDW-who knows why? So I usually get up at 4 or 4:30 am sometimes & do the laundry. It is quiet, no one around and I can take a book or mag with me and enjoy some peace & quiet. Usually at night I get the laundry bags situated, make sure the suitcase is all set with the detergent, etc... in case I wake up & want to do a few loads, then I am all ready to roll (excuse the pun!).
Hope this helps!