It would depend on the type of steel in the frizzen. What you did for your stikers will probably work fine. If your frizzen is cast steel you might want to use the method that Bud Siler recommended for his lock kits. After oil hardening, lay the frizzen on a 1/2 inch thick bed of sand on a steel lid ( I use one from an old oxy-weld pellet can, it's dished). Lay this on your kitchen stove burner and crank up the fire. Make sure you have cleaned the frizzen so you can see the colors. Watch the frizzen as it gets hotter and when it turns a straw color, take it off the fire, set it aside and let air cool. Frizzens I've done this way have lasted for years with very good service.
I can't guarantee that all cast steels will work this well. Recently, I forged a striker from an old file and tried the same method. I oil hardened to prevent cracking and drew the temper on the sand bed just like the frizzen. Didn't work. I ended up water hardening with no tempering to get good sparks. I would try the oil hardening/ sand tempering first, and if that doesn't work, try the other.
