I hate being the asshole who always has to correct things but a couple of those listed have merit in the grow world.
1) Stress like a nail through the stalk or the breaking of a branch can have a effect we desire on our plants. It creates stress in the plant and as a reaction some pplants are known to produce more resin in a defense mechinism. indians used to use the nail in the stalk method a lot. I don't agree with it but do know that some stress at the correct times can increase yield and resin content. I also don't recommend anyone trying the stess method.
2) The magnets....well when I owned a small grow site there were a few extreme experimenters. A few from australia were trialing a new device for soil and hydro growers and it the growing method was termed quantumponics. It utilizes magnets and a electrical charge. The company that used to make the systems is no longer in production due to some reasonn or another. Here is a link to their site. It doesn't show much info and a search didn't bring up a lot of info but I saw pictures and read some astonishing grow reports from some using basically...magnets.
