Hi: I have started alot of Proliferations both in water and directly in moist soil and both methods work. I remove any old or dried leaves from the prolif to make sure the root area is exposed to the water or moist soil. If I do them in water I leave the water level just above the bottom of the prolif., where it attaches itself to the scape. Check them daily and change the water daily, as soon as a root starts to appear I place them in moist soil. I cut the scape about 2 inches above and 2 inches below the prolif. The scape anchors them in place when you put them in the soil. The scape will eventualy dry up/rot and can be removed at that time. If the prolif. has visible roots when you harvest it I would skip the water and place it directly in moist soil. Be very careful not to break the new roots while handling/planting the prolif. I have about a 95% success rate with this method. The odd prolif is not healthly enough to produce roots and will rot and die. These would not be healthy plants and you probably would not want them in your garden. I have never had aphids, but if they appear you could wash the prolif in dish soap and water to get rid of them. If the problem persist you might want to give them a spraying of house and garden raid, I am sure that would get rid of the aphids. I hope this is helpful.

I only tried water method. In most cases they grow roots, then I plant. Last year I had a lot of prolifs, all rooted in water and planted, and all lived.
Check out Jean's thread about prolifs, too!