I've never "watered" my leaves, but I sometimes foliar feed. There is no need to water leaves, in fact it is dangerous since the pools of water act like a magnifying glass in the sun and fry the leaves. You should not foliar feed after a 2-5 weeks of budding (depending on density), since it's a good way to induce bud rot. If a plant is growing well buds can actually grow completely around some moisture, then you're screwed.