Shaykh Sulaymaan bin Abdullah bin Abdul-Wahhaab is the author of the great work, "Tayseer al-Azeez al-Hameed Fee Sharh Kitaab al-Tawheed", an explanation of Kitab al-Tawheed. In the chapter dealing with magic, the author (rahimahullaah) states (Dar al-Simmeemee 1428H, 1/681):

And they differed as to whether a magician disbelieves or not, so a faction from the Salaf held the view that he disbelieves and this was said by Maalik, Abu Haneefah and Ahmad, whose associates said, "Unless his magic was with potions and fumigation and giving to drink that which harms, then such a one does not disbelieve." And it is also said that he does not disbelieve unless there is shirk in his magic, then he disbelieves, and this is the saying of al-Shaafi'ee and a group (of others).

Al-Shaafi'ee said

When he learns magic, we say to him, 'Describe your magic to us' and if he describes that which necessitates kufr, such as what was believed by the people Babil (Babylon) of seeking nearness to the seven stars (through worship of them) and that such (acts) are done through which it is sought from them (the stars) then he is a disbeliever. And if it does not necessitate kufr, then if he believes in its permissibility, he is a disbeliever [and otherwise not].

But upon verification (of the matter), there is not any difference between the two sayings (in actuality) because the one who does not make takfir (declare the magician as a disbeliever) due to his belief that he brings (magic) without committing shirk - whilst it is not like that - rather he does not bring the magic which is from the direction of the devils except with shirk and worshipping the devils and the stars. It is for this reason that it has been called kufr in His saying, "We are only for trial, so disbelieve not (by learning this magic from us)." (2:102) and "Sulaiman did not disbelieve, but the devils disbelieved, teaching men magic..." (2:102)...

And as for the magic of potions and fumigation (using smoke) and what is like that, then it is not magic (sihr), and if it is labelled as magic, then it is done figuratively, just as a far-reaching, powerful speech and nameemah (carrying tales) are also labelled as magic (sihr), however it is unlawful, due to its harm, so the one who does it is to be giving severe disciplinary punishment.

This is clarification from another Scholar that not all of what is labelled as "magic" actually constitutes disbelief that expels from the religion. Refer also to the following:

• Imaam al-Shanqeetee's Clarification and Verification on the Magic that Expels From the Religion - (see here)
• Shaykh Ibn Baz; That Which Makes Magic to Be Kufr is Worship of the Jinn and Seeking their Assistance - (see here)

And from these discussions it is clear that those who use potions and likewise make use of the special properties of things allowing them to bring about certain effects (to trick, deceive or harm the people) and likewise those who use trickery (like sleight of hand) all of which is done without the use of devils, then this does not constitute disbelief, rather it is something unlawful and severely prohibited.