I successfully used the pomodoro method during my PhD. I just couldn't bring myself to do the really boring stuff like the nth iteration of corrections on a section of writing. I developed some features for emacs so I could have my pomodoro timer right there at all times. It also means I have logs of exactly what I worked on and for how long.

But by far my most productive times are when the problem is clear and I feel compelled to solve it. I've always thought that I'd be overall a much more useful person if I could hack my brain to be compelled to do what needs to be done rather than whatever random thing has taken my interest.