When a ger finishes their conversion, must they tovel (immerse in a mikvah) their dishes? Does it matter if they had toveled them previously?
Shevet HaLevi 6:245:2 rules that he would have to tovel them with a bracha. He doesn't distinguish if they were toveled already beforehand and I fail to see why that would make a difference.
Tzitz Eliezer 22:49 rules that they should be toveled without a bracha, reasoning that perhaps the tevillah of the person works to 'elevate' him along with all his property.
R' Usher Weiss shlita (Minchas Osher) argues that he doesn't have to, based on the Chazon Ish's principle (Shvi'is 7) that if there's a halacha that comes up all the time and is not a fringe case, and nobody (mishna, gemoro, rishonim, poskim) mentions it, that is an indication that there is no such halacha. This is such a case, since it's relevant every time someone converts and nobody in the past has mentioned it until 50 years ago.
The shiur (Hebrew) is here: click on the one from תשע"א and see from 30 minutes on.
As mentioned in @Limos answer Rav Asher Weiss deals with this question. I will be detailing what is written in his Shu"t Chelek 3:66(itvshould be known that I did not listen to the shuir limos linked).
Rav Asher Weiss notes that he heard from both the mouths of Rav Eliyashiv and Rav Chaim Kaniefsky that a ger is obligated to tovel their keilim with a bracha. However,Rav Weiss explains that such a din isnt mentioned by the Rishonim or the poskim,and he qoutes the Chazon Ish which is qouted in @Limos answer.
He continues by noting that the din of tevilas keileim apllies only when the utensils are being tranferred from one reshus to another,and a ger doesnt change his keileim from reshus to reshus. He also notes that the halacha has to be analogous to the father of all cases which is klei Midyan,snd that was a change of reshus. Thebfact that a Jew can borrow a kli from a non Jew and use it without tevila also proves that a ger shouldnt have to tovel their utensils.
He then qoutes the Mahari HaLevi 1:109 that asks why the Jews didnt have to tovel their utensils after matan Torah,and he answers because such a halacha does not exist. The Marshag 3:48 says the same as well.
The last and most fascinating source he brings is from the Shem M'Shmuel(Parshas Matos year תרע"ח pg.403) in the name of his father the Avnei Nezer who says that when the ger is tovel it works for his utensils as well just like the din by Temurah 30b.
Rav Weiss ends off saying that mikar hadin a ger does not need to tovel his utensils but according to the Marshag there is a benefit to tovel without a bracha...and תבא עליו ברכה
All opinions exist, as R Michael J Broyde reports in an article in Hakirah vol. 26 p. 146 (Are Converts to Judaism Required to Immerse Their Utensils after Conversion?)
- Avenei Nezer and Shem MiShmuel rule it is not required as the convert's dishes get immersed with him/her metaphysically once (s)he converts
- R Ovadia Yosef rules it is not required since the convert does not acquire the dishes anew from a non-Jew
- R Asher Weiss rules it is not required as there is no trace of such a requirement in the Talmud or earlier halachic codes and since there is no transfer from person to person
- R Shmuel HaLevi Wosner rules it is required since it was owned by a non-Jew and is now owned by a Jew - so is also the ruling of R Yosef Shalom Eliashiv and R Chaim Kanievsky
As a result, in practice, the current chief Rabbi of Israel, R Yitzchak Yosef adopts the view one should immerse metal utensils (since their obligation is d'oraita according to many) without a blessing and one doesn't need to immerse non-metal since they are d'rabbanan and one is usually lenient there.
The Manhattan Beit Din for conversions under the guidance of R Hershel Schachter follows the middle position of immersing without a blessing.
Last, the most creative option is to have the convert purchase a new metal utensil which requires immersing, do it with a blessing and aim to cover the rest of his/her utensils immersed right after.
See the original article at length for sources.