I personally don't understand why The Anti-Lazarus Pit Movement has any credible argument regarding it "not being realistic." It's quite simple AND realistic in Nolan's world. It's not like it has to be some swimming pool filled with magical green goo from Planet X.
There are plenty of herbs in reality that have healing properties, for example. This is basic science. Eucalyptus oils and leaves improve concentration and reduce stress. Elders repel colds, fevers, rashes, burns, and teething. Lemon Balms stop insomnia and anxiety.
It's based on fact. Herbs weren't an important key to the
Resident Evil games just for the hell of it. They were scattered throughout the mansion and city because doctors were hopeful that they would help cure zombie test subjects. They help you heal as you play the game as well. Not the best example, but it's relevant in the world of fiction.
The Elder for example is part blueberry. Blueberries, spinach, and onions, just to name a few, are linked to cancer prevention. Green Teas have antioxidants that are linked to cancer prevention, and longer life expectancy. These cancer fighting agents come from plants, and can be purchased at your local grocery store. It's been proven to help the process.
I don't see why it's so unreasonable to link any of these things to the rare blue poppy flowers from Batman Begins. The Blue Poppy could be one of the herbs that has healing properties in addition to hallucinogenic properties. Why is it so ridiculous to have the League of Shadows create some kind of thick, green soup that combines herbs into a pit that helps heal someone through therapeutic means?
Women go to the spa and have a mud bath. They pay big bucks to have the herbs and vitamins in
liquid dirt soak into their pores. They freakin' put slices of cucumbers over their eyelids. How is that any less ridiculous than a pit in the desert filled with medicinal herbs??