It is not very advisable to water the leaves and buds, as some problems may occur, for example, destruction of trichomes, insects, fungus, cooking by the sun..., I just preffer to wet the soil and let the roots absorb the water.
I didnt foliar feed for years and then I learned about the benefits of Amino Acids, Kelp, Fulvic acids and Humic acids so I gave them a try. The plants loved it and the brix went up a couple of points but the mess they made in the res was more than I could take so now I foliar feed once a week up to the 2nd week after the flip, the plants love it. The brix on the plants outside jumped from 12% to 20% 2 days after I sprayed them. Bugs cant even see those plants.
One of mother natures cruel jokes on me is the plants love kelp and amino acids in flower but I wont risk it so I am testing liquid supplements in the res, without great luck.
Keep the environment in check in your grow room and you wont have issues with mold or mildew. If the humidity is in the 70% range in your grow area dont foliar feed because you already are.lol