No i haven't. We had the privilege of being able to take violin lessons at a Suzuki academy and although we are not affiliated with them any longer I believe they played a tremendous role in how my daughter has learned violin. I took classes as well. it is not mandatory but advisable.
My daughter is 8, she started to play when she was 4 - she will play for the first time -side by side- with the professional symphony orchestra in a concert this coming Saturday - needless to say we are very proud- now that being said it was not easy and it has ups and downs like everything related to children education. But I must say that I honestly believe that it is impossible or better said very unlikely that a child can learn without live instruction. I was told one in a seminar that a child needed to pay attention to 18 different variables when playing just one note. Piano is different you press the key sound will come relatively accurate (depending on piano tuning) but with violin is not just when or where press, is the finger position and not just that one finger, all of them, the angle of the wrist, the arm, the head even the feet. The amount of pressure, the length of time, the amount of hair used ( hair from the bow
) ... It is too complicated to be done cold turkey in fron of a tv while the violin scratches ( that's all u will get the first year ) therefore do not expect immediate rewards from the music point of view.
Suzuki is famous because it places the kid in an win win all cover support system, where the teacher is teaching you as much as the children about the importance of having stress free lessons, therefore they teach parents so we vcan experience at first hand how difficult it is to coordinate all the variables at once, they also place a heavy weight in group classes which are set up as a place where your child will be taught and celebrated all the time, therefore kids are motivated to come back again and again. Google the method. They are the most famous and reliable method in my humble opinion, if thought for a few years kids are able to join any school and carry on with progress. But the beginning is crucial to get a kid to love or hate music.
Only problem with Suzuki they delay reading music until book 3 typically but we started and the transition was ok, remember they already have the perfect pitch in their heads and they are great at memorizing stuff so if they are motivated correctly it does not take too much time. Again it all comes back to the teaching and the support at home. Not pressure or nagging pls.