There is a popular myth that one can use a keli, a vessel or utensil, without toiveling it in a Mikvah, without immersing it, the very first time, or even two or three times. This is total nonsense, as according to Halacha, if one buys a Keli from a non-Jew, they are not allowed to use it, even for the very first time, without first dipping it in a Mikvah. I do not know where this myth came from; perhaps the source of this myth is that there are disposable Kelim, where the first time one uses such a Keli, it is still disposable, and therefore it does not require Tvilah. Once one is planning to use a disposable Keli on a regular basis, there is a reason to suggest that it should require immersing in the Mikvah. People must have assumed that this is the case with everything, and that there is a one-time dispensation. This is absolutely incorrect, and any regular Keli needs to be toiveled even for the first time it is used.