10 year old fixer may work, but 10 year old developer is a bit more dodgy.
Unless you use powder, of course. I had some Kodak DK50 in 2011 that was from the 1970s, and it worked fine (obviously). Right now I'm using some D76 from the 1980s, and that works just like the new stuff you buy today.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh