Betterfelt slippers are very low maintenance. In the first few weeks they will shed some wool and you can just remove the loose wool and throw it away. This shedding process is normal and will not continue though the length of time and will vary from person to person.
Wool felt is dense and due to the lanolin will repel dirt and water. On a daily basis they should be aired and on occasion you can vacuum clean them. There really should be no need to wash them but if you do drop something on them, try to absorb it right away before it sinks in and sponge clean the area gently with some cool water and a little bit of soap designed for wool (or mild shampoo). It is best not to use too much soap as you do not want to get them completely soaked and it may be hard to get the soap out.
After washing them with water, press on them with a towel to remove any excess water in the felt and then put them on to shape them and lay them to dry away from heat on a dry towel. Using warm water (over 30 degrees) or placing them near a heat source while they are wet could lead to shrinkage.
We do not recommend washing them in the laundry machine.
As well, you want to keep the leather soles from getting wet as they will dry out and crack. You can use a suede brush on the leather soles.