If you have a fan blowing on them to dry after your spray them down you should be fine. Rot will only happen if the water sits in the buds to long. Can always give them a good shake to make sure you move the water off them after about an hour. Also I wouldn't worry about re veg, if your using 1/4 strength. I have known people that only use veg nutes all the way to harvest. Is it the best thing to do, no, but it works and they don't reveg. And yes the light change is the most powerful aspect for flowering. I am not saying it couldn't happen, but I have never seen or heard of a plant re veging just based on what your feeding it. It would have to be very strong feedings of N or combine with some other stress indueds onto it. You use 1/4 the strength you normally use, you should be fine.
I went ahead and foliar fed yesterday and ended up passing out around 7 so I didn't get to check and see if it helped any. I checked this morning and they look awesome. I can't tell for sure because it their dark period till off-peek around 4pm. But ya, they look like they've perked up. I'm just realizing now that you had said veg but I had put bloom 1/4 strength instead. I guess I was soo fried and tired I just mixed what was at the mixing station without thinking, oh well. Either way they look to be much more green and happy.
Thanks for your help
@Hotboxbudz. I always read and saw that people were bashing foliar feed during flower and just never thought twice. But I looked up when you suggested and actually found a solid base of people who swear by it. Saw a few video's of guys growing massive beast plants with cola's the size of coke bottles, misting the shit out of the bottom sides of the leaves. Makes sense though right? I mean under normal weather conditions an outdoor plant is going to be fine after a heavy rain. Found another video of a guerilla grow of about 15 or so 6'+ plants. Heavy rain for 3 days before he chopped and even while he video'd the harvest it was raining, buds turned out normal.
I wanna go off on a tangent for a sec. Has any one tried a 1/4 strength nutrient foliar spray on actual tomatoes, not metaphorical "tomatoes" that actually mean marijuana, but actually red spherical fruit producing tomatoes plants???