The grifolic poncho degrades over 30,000 charges of combat, and will revert into a mycelium poncho web when fully degraded. A partially degraded poncho can be repaired using grifolic flakes - 35 per 1% - which also requires 78 Crafting and some thread, granting a scaled amount of Crafting experience. If it fully degrades, it will need to be re-created from the poncho web.
The poncho can be cleaned at any point to return the mycelium poncho web, and half of the remaining charges in grifolic flakes, rounded up - e.g. an 80% charged poncho will return 1400 flakes. Additionally, alchemy performed on the poncho returns a scaling amount of coins based on the remaining charges.