How do you use Congealed Acid to get past vines?

[JC the Builder]

I double-click the acid and nothing happens. I double-click the door and nothing happens. I've seen other people open the doors.

 

[Lord GOD(GOD)]

The congealed acid is for a seperate quest, the acid slugs also drop a little round dark brown thing (like the venom sacs/gourd graphic or w/e) which you use on the vines.

 

[jbfortune]

Which vine is it? I have the acid but it says invalid target

 

[DevilsOwn]

room just past the acid slugs, on the west wall south of the door ~ it displays a message if you click it and do not have the acid sac