A patient with kidney stones can use paper strainers from the paint deparment of a hardware store, kitchen strainer, or coffee filters when they urinate if they don't have the stainer that was provided.
I provide a strainer for my patients with kidney stones to use when they urinate. However, if they don't have this with them, I tell them that they can use paper strainers from the paint department of a hardware store, a fine mesh kitchen strainer, or even disposable coffee filters.
-Terry Ishihara
Phoenix