Go to Daiso, at the shoe aisle.
Look for a brush with metal wires one side and rubber wires one
side. Lightly brush out the gritty bits on your suede
materials and then brush again with any sides to raise the
suede.
If you really want to. Soak and rinse your suede shoes
quickly and be careful with drying them. Dry with cloths to
squeeze out the water. Stuff it with cloth and dry it totally
without sunlight or water stains might mark your suede.
After that. Spray liberally with 3M uphosterly spray to
protect it further. Leave to dry.
You should try to spray 3M sprays before you use or wear any
suede materials to protect it against humidity and rain.