Found it thanks! also those sacks are hard to distinguish on where their gas can reach.Start from the very first shrine. Should be the first one in the Forest of the Shrine. Head Right and stay at the lowest level possible. When you start seeing tentacle flora, you are in the right place.
Also, when you encounter sacks that puffs out massive amount of pink gas, stay and even crouch to areas where it doesn't cover. Even if the uncovered area seems small.