This is not my formula, i got it from Alpa6 a beekeeper in Col., he uses it on his hives (i think he is a commercial beekeeper) with good results. It has worked for me and i will use it again if need be.
2 qts. of water
2 qts of sugar
15 drops of Thyme oil
28 drops of lemongrass oil
28 drops of spearmint oil
3 teaspoons of lecithin
Before i mix it together, i soak the lecithin in a 1/4 in.of water in a cup, let it soak overnight, then strain it through a cloth or ? to catch the flakes so when it goes through the fine mist sprayer it won't stop it up.The lecithin is used to let the oils mix with the water. When i use it, i spray each frame bees and all before the honey flow (first 70F day) then wait two weeks and spray again. I won't spray again until late Sept. or Oct. and only one time, be sure you don't forget and double dose the Thyme oil

i've heard it will cause massive fanning and run most of the bees out to the front of the hive and on the landing board

. Jack