I do not have any experience with cuttings so can't say how they would do. I would think healthy plants would be much easier to get clones rooted from. Maybe someone will chime in with more experience in that area. On the seaweed foliar, it could be several things. Obviously the concentration is important. Studies have also shown foliar is better absorbed at a lower PH. I like to foliar feed with a PH in the 5.5 to 6.0 area. Also the plants are much more receptive if they are in the correct state. There are some guides out there on when to foliar feed. Many recommend with the lights out. I don't like to leave the plants wet in the dark. I like to do it early in the morning ideally shortly after lights on. I have dimmable lights and I also turn the light level down for an hour or two after foliar. If the light is too bright the light can burn the leaves. If it is also not ideal if your temps are too high like over 80 deg F