Which Linux distributions do you use?

[rbmj]

If you've mounted the ntfs partition correctly, you're good to go. As long as it's mounted, the concept of a partition is transparent to the userland tools. It'll write to it as if it's on the root and the filesystem driver will do the actual write. Most linux distributions have the proper support to write to ntfs enabled. If you can echo foo > bar, then you can dd.

And if you can't, it should stop you by giving you a permission denied message before it lets you do something that can nuke the partition. It's only "disk destroyer" if you start playing with outputting to files in /dev - that's the only time it actually writes bytes to raw disk - and really anything written to those files can be dangerous, just dd does it the most. They might be special files, but they're still just files, and dd doesn't do much of anything special - it just moves bytes around, like a really low-level cat.