Thank you for SHARING!
You do not need to replace until the fabric or threads break.
As long as you gently squeeze when 'milking' or 'juicing', and keep it micro-organism free* (bacteria, mold, viruses, fungus...) it could last a long time.
Keepin in mind that someone who uses their nut milk bag/strainer multiple times per day will have a different length of use than someone who uses it a few times a week.
*We recommend boiling in water for a minumum of 15 minutes.
