yes, alcohol does stunt growth in some plants. It will stop the plant from
growing too tall, but the
flowers will retain their size and colour. Plant,s like humans can die of alcohol poisoning, so be sure you're proportions of water to alcohol is right. I remember reading 7:1 water to alcohol. I'm not sure if only drinking alcohol works, maybe the rubbing alcohol does as well. The alcohol experiment is often done to narcissus, but it will work for amaryllis as well. As to whether or not it works in soil, I honest have no clue

Bulbs that haven't been cold enough will bloom on short stems (that's how you tell you had a mild winter: the tulips, daffs, and hyacinths have short stems)