While you can't erase the tried status as far as I can tell, you can at least set it to 0 stars by doing the following
Hover the mouse over the star rating area on the page.. it can be over any of the stars. Right click that and copy the link, you should get something like this (I did this for 10 Corso Como, and was hovering over the #2 star)
http://www.basenotes.net/cgi-bin/wardrobedo.cgi?5-26124163=2
See that part at the end that reads: =2
Well, that's because I was hovering over the number 2 star. All you have to do is paste this address into your address bar, and then change that last number to 0, and the fragrance will be set back at 0 stars.
so this
http://www.basenotes.net/cgi-bin/wardrobedo.cgi?5-26124163=2
becomes
http://www.basenotes.net/cgi-bin/wardrobedo.cgi?5-26124163=0