Ski boots get damp and stay damp, and a warm damp liner is exactly what mould and bacteria want. This neutralises the odour rather than covering it, which is the difference between a treatment and an air freshener.

Eliminates mould, mildew and odour in ski and snowboard boots
Neutralises rather than masks
Fast-acting and biodegradable
Professional-grade

The real fix is drying. A spray manages the symptom; boots that dry properly between days do not develop the problem. Pull the liners out at the end of a wet day, or use a boot dryer — gentle warm air, not high heat, which damages liners and changes a fit a bootfitter has set.

Worth knowing: a liner that has been damp for a long period also packs out faster, so the smell often arrives alongside a fit getting sloppy. If both are happening, the liner may be the issue rather than the boot.

Useful in a shop too — nobody wants to work on a boot that has been in a bag since April.

See boot fitting and accessories.