Soapy dishwater is commonly what I use on aphids. I used an orange scented liquid dish soap recently, and it seemed to do the trick. Doesn't matter if it is Dawn, Ultra, or any particular brand, as long as it smells soapy and forms bubbles and suds.

Aphids tend to dislike strong scents. They also are weak and can't climb well on slippery, smooth surfaces.

Other things I have tried that work a little bit are rubbing crushed mint leaves on the stalks. Hot red pepper and garlic tea. Nicotania, I have also used to make a tea that deters aphids. The nicotine in the leaves basically kills them.

Once the aphids take over, there isn't much I have found that works. The ants relentlessly bring them back. Rejoice if you find an antlion causing them some havoc.