here's something I found:(scroll down to Apple Cider Vinegar)

not sure if this is what you used but it could be worth a try. hope it helps.

Here is a link that might be useful: Golden Harvest Organics

Depending on the shrub try and thin some branches to provide air circulation for the plants. Then ask yourself do you really want to take the time and trouble taking care of these two shrubs. Sometimes the answer to this type of problem is to remove the problem and plant something requiring less care.

To spray "something" on what appears to be a problem can often do more harm than the "problem". First this "fungus" needs to be identified, might it have been Powdery Mildew? Something else? Then the growing conditions of the plant needs to be looked into and if those conditions are not what that plants needs those growing conditions need to be corrected.
Plants growing in good, healthy soils and an environment they need are less likely to have insect pest and plant disease problems.

The Rose of Sharon had bloom rot last year which(after help from this blog) I attributed to a lack of sun. It was in a rather obscure location in the yard and I just realized what it was and it's potential. We trimmed limbs on the tree above it to give it a bit more sun and sprayed it last year with the apple cidar vinegar concoction and it did seem to help.

The Lonicera is in a different location but still in the shade a lot of the time I can't really help that. The trees above it are too large to trim. The leaves on it get black spots I think and just turn brown. The blooms aren't affected. This seems to happen later in the summer. I don't think I would describe it as a powderly mildew.

Thanks for the link! This provided me with the ratio of Vinegar to water which is what I needed. We can't remember if the "recipe" we used also called for horicultural oil or dishsoap or not. We had looked at so many different rememdies at that time. But at least we now have a starting point. Thanks!

Why does it need to be apple cider vinegar? Could you use white vinegar?