The use of borax is to keep the roe dry so when you're using it, your hands don't get sticky with the goo etc.
Personally, I dislike using borax, I stopped using it around 5 years ago, because it acts like sand when it gets inside the reel.
I like to salt the roe or soak my roe in a salt solution for an hour or so, to draw the water out of the eggs so they are firm (but not hard, the longer it is salted, the harder it gets). For drift fishing in the Vedder etc, I like to purchase a jar of Procure Double hot red. The closest shop to you would be Berry's Bait and Tackle for that. Sprinkle the procure on the roe and let it sit for awhile. Then it is ready.
For fishing down here (Tidal Fraser), the roe can be used after it is salted. Store it in borax if you want, but I find that it makes no difference to the fishing result.