False eyelashes can be reused multiple times if they are properly cared for and cleaned. The number of times they can be reused depends on the type of lash and how well they are taken care of. Synthetic lashes can be reused up to five times, while mink or silk lashes can be reused up to 20 times. Here are some tips on how to clean and reuse false eyelashes:

How to Clean False Eyelashes:

1. Place your false eyelashes on a paper towel.
2. Saturate a cotton swab with micellar water or eye makeup remover.
3. Gently wipe the band and the fibers of the false lashes to remove any leftover mascara, dirt, and excess oils.
4. Repeat this process until the lashes are completely clean.
5. Let the lashes air dry on the paper towel.

Tips for Reusing False Eyelashes:

1. Remove the lashes with care to avoid damaging them.
2. Store the lashes in a clean, dry place.
3. Avoid using facial oils and oil cleansers on false lashes, as they can make it difficult for lash glue to stick to the lashes the next time you use them.
4. Use a lash brush to remove any extra residue clinging to the falsies.
5. If you notice any irritation or symptoms of an infection in your eyes after applying false lashes, it could be the result of bacteria spreading after sharing cosmetic products with others or using old lashes.

It is important to note that false eyelashes made out of synthetic materials are usually considered disposable, and ones created out of synthetic materials even more so because of their cheap and affordable price point.