The original WD-40 only acquired its false reputation for being "good at everything" due to some idiots who write for the monthly comics. It was originally sold as a water repellent, which is does do rather well. Quite good at shifting oil and grease too.
They now seem to have a family of specialist products, so I would encourage people to be careful in describing what they are using or recommending. If you mean the penetrant variety, please be sure to clearly say so, so that umpteen people don't feel that they have to jump in and correct you. This is a general point, to hopefully make things clearer in future, and I am not having a go at anyone in this thread.
There are similar problems with POR15, a family of very different products relating to paint and rust protection. People should try to remember to say which POR15 product they mean. I imagine that there will be other brands where we need to be careful too.
Have fun.