sponge bag 
noun British
A toilet bag.He arrived hours later with a huge case, the contents being four bras (no knickers), one nightdress he had retrieved from the laundry bin and an old sponge bag of his containing a razor and shaving cream....
- All that may sound like an immense amount, but if you take them out of their bulky packaging they will pack into your sponge bag relatively easily.
- I hate packing, it makes my natural tendency towards anticipatory anxiety all the worse, but the excitement of having a new sponge bag is strangely comforting.