In majority of cases, the visible outsole edge of a shoe can be cleaned using a damp cloth to wipe over the surface. For a deeper clean and to help maintain the look of your shoes, a foam shoe cleaner may help.
For excess dirt underneath on the outsole of a shoe, first brush away excess dirt with a nail brush or similar (unless you have a great door mat!). Then clean further, if needed, with a damp cloth.
Some of our styles have soles made out of Polyurethane. The features of this compound offer lightweight construction with stability and cushioning. To have the benefits of a soft and stable material, the material does come with an expiry date. The sole will show the effects of deterioration over time, whether they are worn often or stored in a cupboard. Though Polyurethane wears well, it doesn't like being shut away in a box. It might sound obvious, but the fact is our shoes are designed to be worn. So wear them and enjoy!