```python
def path_clean(path: str) -> str:
    """Remove every segment of two dots by dropping it together with the segment standing before it."""
    if not path:
        return ""
    
    segments = path.split('/')
    cleaned_segments = []
    
    for segment in segments:
        if segment == '..':
            if cleaned_segments:
                cleaned_segments.pop()
        elif segment != '.':
            cleaned_segments.append(segment)
    
    return '/'.join(cleaned_segments)
```