Circumventing the need to Tovel-Giving the vessel to a gentile and then borrowing it back:
Vessels that are borrowed or rented from a gentile do not require immersion. Accordingly, in a case that one is unable to immerse a vessel in a Mikveh, such as on Shabbos or in an area without a Mikveh, he can give the vessel to a gentile and then borrow it back and use it without immersion. However, this only helps to allow one to use the vessels without immersion on temporary basis. It is however forbidden to use the vessels permanently without immersion, even though they are considered borrowed from the gentile. He is to thus immerse the vessel without a blessing [or immerse together with a vessel that requires a blessing] in a Mikveh at his first opportunity.
 Michaber Y.D. 120/8
 Michaber Y.D. 120/16 and Admur 323/8 regarding Shabbos; Rama 120/16 that so applies even during the week in an area without a Mikveh; Mordechai Beitza Reemes 677
Other opinions: Some Poskim question this allowance to give a vessel as a present to a gentile and then to take it back, as this is not a true acquisition to the gentile and is rather Harama. Additionally, it is forbidden to give a present to a gentile.[Rashbash 468; Pischeiy Teshuvah 120/15]
 Taz Y.D. 120/18; Ketzos Hashulchan 146 footnote 6 that this applies even according to Admur, and the reason Admur did not state this explicitly is because he is dealing with a case that one only has this vessel to immerse.
 Admur ibid; Taz Y.D. 120/18; Chelkas Binyamon 120/133
The reason: One cannot use the vessel forever on the basis that it belongs to a gentile as when an item remains forever in the hands of the Jew it is similar to him having acquired it. Furthermore, it is similar to a borrowed Tallis which requires Tzitzis after 30 days being that after 30 days it appears as if it belongs to him. Based on this it should be immersed even with a blessing. Nevertheless since I have not found the matter explicitly ruled in Poskim I am hesitant to rule this way, and rather one should immerse another vessel that requires a blessing together with it. [Yoreh Deah Taz 120/18]
Other opinions: Some Poskim rule it is not necessary to immerse the vessel. [Kneses Hagedola 120]