If a dog drinks or licks from a vessel, the Prophet (peace be upon him) commanded that it be washed seven times, the first of these washings being with earth or dust (or a comparable scouring cleanser in its place). This shows that the dog's saliva is najis and is only removed by this specific sevenfold washing rather than an ordinary rinse. The majority (Shafi'is and Hanbalis) take this as the binding ruling for the vessel; scholars differ over some related details, but the container the dog drank from is purified exactly as described in the hadith.
Evidence — the daleel
Sahih al-Bukhari 172 (Abu Hurayra) ṢaḥīḥSahih Muslim 279 Ṣaḥīḥ
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.