Neem oil, Dishwashing liquid (not detergent), Garlic barrier, Listerine (Blue mint), Pyrethrin concentrate, there are other ingredients available to the home grower not wishing to own a store bought item that rarely ever work for me. And if it did I would have an empty bottle in a few days time needing more the next week. The home neem mix does work for me and I don't squirt the friendly's if I see them. They are usually bigger than the aphids.
I believe the quantity and location of plants infected determine the course of action. 1500 ladybugs are probably not welcome in your house. Bazblitz either is indoors or a porch maybe from the photos in his grow log. I agree about mashing with fingers indoors and small number of plants. Probably will have to do it a few times. Some of those are big. Aphids can reproduce very fast. Aj has a detailed chart graph growth rate here somewhere. I believe they can produce without mating as well.
If you purchase ladybugs they need something to make them want to hang around. They want a secure future for their offspring.
Hope this helps
Mike