Plant in full sun if it’s not too hot. Ladybird larvae also help.

I have found alternating between copper sprays and milk-water (1:10) sprays to be somewhat effective.

If you Google diluted bleach solution for tomatoes, you'll hit on an effective way to treat tomato plants. The guy who uses this writes a lot about it over on TV. He uses it for a mold, but last year I noticed powdery mildew on my cucumbers, and used a VERY diluted spray, like 1 tbsp per gallon of water, and it worked very well.

Gardengal - oops I didn’t realise but it’s only a thing here in Australia - https://en.wikipedia.org/wiki/Illeis_galbula

https://www.sgaonline.org.au/powdery-mildew/

They’re good at getting it off and they flock to cubiter plants.

Would seriously advise AGAINST using a product as caustic as bleach on any living plant, even highly diluted!! And then there is the issue of phytotoxicity and chlorine contamination........

Why not try one of the almost totally harmless home remedies like baking soda or milk first before you resort to something that could just as easily kill the plant rather than save it.

I'm just relaying the information. You probably know way more than me about this anyway. It is a nuclear option, as stated in the linked thread. Try other methods first. I used way less than is even recommended, and it worked like a charm for me almost immediately. The information is there, and the process and methods are well documented by a highly respected grower in the community, and used successfully by many.

http://www.tomatoville.com/showthread.php?t=28509&highlight=bleach+spray

I'll never forget when my father used bleach to kill weeds one day, very diluted and in the process killed all the surrounding plants, frogs and living creatures..Never again..