If a person acquired a utensil from a gentile, such that it requires immersion, may he keep it in his home before he immerses it? Halacha forbids using a utensil acquired from a gentile before it is immersed, and if one keeps it in his home, he might forgetfully use it with food, in violation of Halacha. The question thus arises as to whether one may keep it in his home in the interim, given the risk that this poses.
Halacha in fact allows keeping a utensil in one’s home before it undergoes Tebila (immersion). The Sages did not go so far as to require keeping the utensil outside one’s home until its immersion. Even though there is the risk of a mistake, such a law was never enacted, and one may keep the utensil in his home even before Tebila.
It should be noted that some people mistakenly think that one may use a utensil once before immersing it. This is Halachically incorrect. There is no basis for allowing using a utensil before immersion, even once.
Summary: It is forbidden to use a utensil acquired by a gentile until it undergoes immersion. One may keep the utensil in his home before it is immersed.