If they are on your windows it should be O.K.
CDG

I just use a couple of drops of dish detergent in a spray bottle. Spray at least once a day, keep doing it even if you don't see them, because they're still hatching. The foamier you can get the spray out, the better it seems to work, or at least that's been my perception.

YES Windex. Or any ammonia window cleaner... worked on my aphid problem and fungus gnats also.

How many plants are we talking? How bad an aphid problem?

I think I will spray some on a plant. It is too hot for tomatoes to set and we have a few old adventitious plants. No aphids but I have a good test spot to see if the ammonia does any harm to the plant. I suspect it will not.