Some years ago, I was composing an advert for Raven and I'd put something like 'Your one-stop shop for all your magical and mystical needs.' A friend who was with me at the time said, "You want to take out the 'mystic' bit, it gives the wrong impression."
I still do not understand what 'wrong impression' is implied by the word mystical.
The word 'mystic' comes from the ancient Greek and directly from the Mysteries of Eleusis, It means a person who is involved in practises relating to the Mysteries, an initiate. To me any Witch worth their salt will be involved with the Mysteries, you just can't help it if you are involved with Witchcraft.
To be an initiate of any kind means, or at least implies, that you have entered into a contract which will ensure that you are investigating, or will be taught, about concepts or practises outside the everyday sphere of mundane experience.
What you do with the knowledge is up to you and your own level of spiritual understanding.
It is possible to work Witch magic without reference to any spiritual beings, however they do tend to sneak in when you aren't expecting it. For example: a very simple traditional wishing spell is to find the waxing moon in the sky, blow her a kiss and make a wish.
To any outsider, all you are doing is blowing a kiss to a dead lump of rock which is only glowing in the night sky because the sunlight it shining on it and not on your side of the planet Earth.
But to a Mystic, anyone who is involved in the Mysteries, you know that the Moon is merely a symbol of something far greater. In this case the Moon is the symbol of the Goddess, and by blowing a kiss to the moon you are petitioning the Goddess, asking her to intercede on your behalf and ensure the success of your spell.
I shall no doubt return to this topic in the future, but that is enough to hopefully get your Mystical interest piqued.