Has anybody successfully beaten mealybugs on their houseplants? I tried with soap and with isopropanol and hand wiping every plant and leaf. It seemed they went away, but I noticed they were back today. I was going to try dyna-grow neem oil but people are saying you need to mix it with other things.

I found Garden-safe insecticidal soap which says it kills mealybugs, but there are reviews saying it didn't work for people. Has anybody tried either of these? The neem oil is pretty expensive and I don't want to spend too much but I don't want to waste $ on something that doesnt work. I think they're in the soil. Do you change out the soil or not? We had a lot of expenses this month (car broken into, wallet stolen) so I'm hoping not to spend too much but I don't want to lose my houseplants. :( Any help would be great.