Best rule of thumb is NOT to use white out. Correcting entries are best. Even if you are correcting something that has been carried over for many pages, one entry on your current page will suffice. Reference the entry where the mistake occurred.

The point is that someone reading your logbook should be able to systematically follow your progression. White out makes that difficult - it leaves doubt in the interviewer's mind. Are you hiding something?

Don't let interviewers use their imaginations...