There is a bubble bath bottle at Meowy's Mporium in the exchange bin. First, you should take the hypnotizing kit.
You should go forward with other stuff and you will find more "historical" clothing.
You need to get Cosmo to open up, fully, about his situation.
And he gave you his wig...
It is a piece of clothing... And it has historical value.
Give the wig to Meowy. You can now take the self-foaming fur cleaner.