I used to play in a band that experimented with that tuning because we admired Sepultura who were using that tuning for their Roots album.
I used the heaviest strings available at that time. I had to special order them from Musicians' Friend catalog. I had two basses strung that way and didn't have any problem stringing them.
I did have a problem with the thickest string breaking at the bridge because it wasn't thick at the end. How can I describe it? Many strings are the same guage all the way through to the end, but the heaviest guage string narrowed down, I guess to fit through the hole. That was a point of weakness, however. You wouldn't think the thickest guage string would be prone to failure, but mine were. Maybe thick guage strings are better quality now because the popularity of super-low tunings is much greater than it was when my band used that tuning.
I did have to deepen one nut slot because the thickest string would slip right out when I was playing. That was a real surprise the first couple times it happened. I hated to cut into my Tobias. I didn't really care about the Jackson.
I picked really hard, too, which may have added to string stress. But I felt like I had to. Here's why. When tuned that low, the strings seemed unresponsive and loose...no spring. I felt as if I had to pick hard to get a sound that wasn't muddy, especially playing the open C# or fretting a D, or D#--the lowest notes.
Be careful how you equalize your sound equipment. If you don't experiment with your lows, mids and highs, you may get a really muddy tone. It may take some trial and error to get some life in your sound. You may also have to experiment with the knobs on your bass. My Jackson never did sound particularly good with that low tuning, no matter what I adjusted or how. My Tobias, however, handled it much better.
Oh, how did I tune? I used my trusty Korg electronic chromatic tuner. The guitarists used it too!