Whiteflies, if all else fails

[HiPoha]

Isopropyl alcohol , about two tablespoons per pint of water, more or less at your discretion. Use in a spray bottle. Kills whiteflies dead. Visible results.
I have tried all the recommended solutions here and from the Garden stores, nothing worked. Got some tough whiteflies here.
Having access to bars and pubs throw away liquor, I've gotten some good results using Johnny Walker, Sky Vodka, Bourbon, etc.. but in full strenght.
Another way to get at them is to go under each leaf with a dry paint brush and destroy their homes.

Edit:
Using alcohol has been around for a while. Some people suggest that you can use up to a 50% solution of Isopropyl . That may get costly for a large garden infestation of whiteflies. I would use just enough till you see the whiteflies drop off the plants. Two tablespoons per pint is just a starting figure. Do not use methyl alcohol, ever...may cause blindness.