do I need an additive in my 8 3/4 sure grip?

Hi folks.

I have a (very) slow leak from my 8 3/4. I want to top off the fluid.

Question - do I need to worry about the limited slip additive? When I first filled it, I know I used a bottle of the skunk oil, but I've read online that if I find gear lube that states it's good for limited slip diffs that it isn't necessary?

Thoughts?