Does lukoplakia from tobacco usually go away on its own, and if so how long would it take? i've seen from months to a year on different web sites?

Leukoplakia: Is usually benign condition, and lesions usually clear in a few weeks or months after the source of irritation is removed (tobacco in your case). However, if the lesions show early signs of cancer, your dentist will refer you for a biopsy and treatment which involves in white patches removal. Rec.: see your dentist for evaluation and oral cancer screening.