Private Browsing subsitute for SS. Rated 5 out of 5 stars
May Private Browsing substitute for Secure Sanitizer in securely removing files?This user has other reviews of this add-on.
As a general answer: yes. Consider when SS was developed Private Browsing wasn't available yet.
More in detail: Private Browsing works disabling cache on disk; it uses cache in ram, instead. So if you have a PC with low memory available maybe you prefer to use cache on disk. In this scenario SS it is still useful.
Thanks for your review.