Unlike a number of other, more expensive shoe dryers, Drysure’s Active shoe dryers don’t need to be plugged in thanks to the use of silica gel beads, which are held within fabric sacks.
Using the Drysures is easy. Simply slip the two plastic shells (which encase the fabric sacks) into your shoes and wait.
Once dry, you can easily pop the casing open to access the bead sacks. To reactivate the beads, you can sit them on a warm radiator, place them in direct sunlight or stick them in the oven (excluding the plastic casing) for a couple of hours.
Once reactivated, you need to store them in the plastic bag provided (which I’d prefer to be a little bigger, because it’s quite tight) to keep them dry. I’ve found the Drysures to be effective, especially when drying damp shoes overnight.
To really test them, I submerged a pair of Giro Chamber II shoes for 10 seconds in cold water and slotted a dryer into one of them. After 24 hours, the shoe with the dryer was almost completely dry, with only some of the thicker ankle padding feeling damp when squeezed. The shoe without the dryer still felt damp inside and the padding noticeably damper.
While the Drysures may not dry heavily-soaked shoes overnight, they certainly help things to feel comfier, which I think makes them well worth the price.