Is it ok to use the names of my ex or recent professors in the personal statement? Of course in positive context (how they influenced me etc.) I am not from the USA and in my country it is quite uncommon to write essays like that, so I do not know if it would be ok to use the names.
There is no reason of ethics or custom to prevent you from using the names of professors in your personal statement. Remember, however, that the personal statement needs to be about you, not about your professors, and choose accordingly whether to talk about a particular professor.
Thus, for example:
If you are talking about a research experience that you had as an undergraduate, then the name of the professor that you worked with is quite germane, and likely to be one of your references in any case.
If you are talking about a class that inspired you, then the class and the professor are not particularly interesting for the statement: instead what is interesting is what that inspiration has caused you to do.