Reference for Avodah Zarah 5:12
הַלּוֹקֵחַ כְּלֵי תַשְׁמִישׁ מִן הַגּוֹי, אֶת שֶׁדַּרְכּוֹ לְהַטְבִּיל, יַטְבִּיל. לְהַגְעִיל, יַגְעִיל. לְלַבֵּן בָּאוּר, יְלַבֵּן בָּאוּר. הַשַּׁפּוּד וְהָאַסְכְּלָה, מְלַבְּנָן בָּאוּר. הַסַּכִּין, שָׁפָהּ וְהִיא טְהוֹרָה:
If one takes [eating] utensils from a gentile, [(only metal utensils or earthenware utensils coated with lead (and glassware is like metalware)] — what is wont to be immersed, [that is, a vessel which can be rendered ritually clean by immersion and which requires no other procedure (as when it is used with "cold")] should be immersed [in a mikveh which is kosher for the immersion of women, and its immersion permits it (for use)]. (What is wont) to be purged (by immersion in boiling water) [such as kettles and plates of metal, which are used with "hot"] should be purged [in boiling water. They are placed into a kettle full of boiling water and left there a little. This, after their rust has been scrubbed and removed, after which they are immersed in a mikveh which is kosher for the immersion of women, and they are permitted (for use)]. (What is wont) to be fired (white-heated), [i.e., utensils that are used for dry things], like a spit and a grill, should be fired [until they give off sparks, after which they are immersed and are permitted (for use)]. A knife — shafah and it is (ritually) clean. [He sticks it into hard earth ten times if it has no depressions, and he may eat "cold" with it; or he sharpens it with its whetstone and he may eat even "hot" with it. If it has depressions, he "fires" them. And all of them (the above) — if he used them before he boiled or fired or immersed them (respectively) — it (i.e., what he processed with them) is permitted.]