I would second trying Captan. I think the main issue is you need to do more sprays into the Summer and maybe reduce the spray interval. Captan is pretty commonly used by commercial growers to control Summer rots, flyspeck and sooty blotch. You can buy it from Schlabach’s in small quantities (1lb) for the Captan 50% and Captan 80% comes in 6lb bags for larger growers. The 6lb bags are about $50. It’s also available from other suppliers at similar prices.
With Captan you need to make sure the spray water is acidic. At a pH of 8 half the Captan is destroyed in 10 minutes. A pH of 5 is ideal with 5-7 being ok if your going to spray right after you mix the Captan into the water. You can use vinegar or citric acid to lower the pH. I use citric acid which is found with canning supplies in retail stores. I use a 1/4 teaspoon of citric acid in 2 gallons of spray water. The amount needed will vary with the pH of your tap water. For more info on spray water pH take a look at this-
First Enterprise apple - #25 by mroot
As far as Pageant Intrinsic being the same as Pristine there is no way for the average consumer to tell this. To tell this for sure you would need a lot of technical information which probably isn’t readily available and a technical background that allows you to interpret that information.
To give an example, some time ago I worked for a chemical company that made Hydrochloric acid and fumed silica. There were two grades of acid- steel grade and food grade. Steel grade had more metals and higher sulfites so you wouldn’t want to use it to adjust the pH of food products. On the other hand for the fumed silica the standard grade and pharmaceutical grade were the same. The only difference is pharmaceutical grade required more testing and record keeping.
It’s also common in the chemical industry to have lower grade materials with more impurities. Or a formulation accept products with more impurities if it’s intended with industrial use rather than food use. It is quite possible that Pageant Intrinsic is a product that was developed simply as a way to dispose of off quality Pristine that can’t be sold for use on fruits due to impurities being too high. As a consumer you have no way to tell. So I think it would be wise not to use Pageant Intrinsic on fruit even if you are ok with over looking the legal issues.