I spray my wife’s rose bushes with whole milk when they get WPM, it works. As far as my plants, I’ve used neem oil in veg the one time I had WPM and it cleared it up, never had it during flowering but if I did I would probably try the peroxide/water mix or the baking soda, or heat.
I’ve heard of growers using high temps to eradicate WPM in flowering, get tent to over 95F for a 12 hour period, never tried it as I get WPM so rarely (once in 30 years).