It's fine if they go limp after you give em a nice shower, they are more weighted down... mine always perk up within like twenty four hours anyhow, so no worries if that's the case for you.

I also use foilar sprays to address problems mostly, though I've been hearing about this folar spray that makes plants bushier, I'm not really sold on that just yet.

That said, raise your lights when you spray for five-six hours so and you shouldn't have a problem with burning.