Can the Abyss pouches be used outside of the Abyss? How long before they degrade to nothing?

They can be used outside the Abyss (great for mining essence). The larger the pouch, the faster it will degrade. I filled my large pouch ~10 times and it degraded to its first form, so... about 30 fills for a large pouch to fully degrade.

When using my large in abyss i used to recharge it every 1k nats i made. But it lasted till about 1.1-1.2k i think. So it should give about 25-30 fills before it degrades id say.

You can repair it before it degrades to prevent it from doing so. I repair on the tenth trip.