I am afraid that this is a problem that is difficult to solve with this man as he is used to such filth. It might be beyond repair. Therefore, it is best for her to avoid him sexually as she may catch something from him, if she insists on staying with him or she has no other place to go to.
Ideally speaking, divorce would be the best solution as accepting his condition would only deteriorate the levels of her Iman.
She should supplicate to Allah and pray that Allah may guide him back to the straight path.