I remember taking 3 days to clean up my first mess with that ...function but thanks to Dan, found a way to use it when needed and just brushed the rest together.
Hunting down blocks was a nightmare untill I discovered that if they were involved in a group, the group had to be opened to locate the offending artifacts.

Hollow block should be used with care too, take the time to get the size right before commiting the hollow command or if you need to resize, rebuild then re-hollow as more probs can crop up when scaling a hollow block unconstrained.

In theory they all work fine...untill you compile and then the engine decides to add more to the mess untill you select 'dont snap vertices' but then...more probs as the subtract might end up looking good with this option but other blocks decide to play up and so on add infinitum!

So now I hand build doorways, window and the like (oddly enough, most other users dont get the results I get and vice versa...strange)