Originally Posted by
prj71
Got this response by Park Tool to a negative review on their website:
"Thanks for your review! We suggest always replacing damaged tubes/tires as soon as possible to prevent accident or injury while riding. Our patches can last a long time, but there are many variables that can affect the performance of the patch. We recommend not testing the patch by inflating tube while outside of mounted tire. This may stretch tube body and weaken patch bond."
Basically, it says they can a last a long time when they last a long time, but sometimes they don't.
Seems totally unsurprising that some people find it works better for them than others.