How cleaning equipment moves residues
A cloth used on one bench and then another carries whatever was on the first. So does a brush, a scourer, a bucket of water and a mop moving between areas. In a kitchen preparing a range of dishes, that movement can defeat a separation regime that is otherwise carefully maintained by the people preparing the food. It is invisible, which is why it persists.
The control is the same one used for hygiene generally: dedicated equipment per area, adequate quantity so nobody has to improvise, and storage that keeps the sets apart. It costs very little and it removes a route that is genuinely difficult to manage any other way. Where a venue has an existing colour scheme for allergen separation, the cleaning equipment should follow it rather than run in parallel.
