I thought zaja blue juice was a synthetic or synthetic blend... if not then chime in
I would not break in my horn with it. I would do the intial break in with some alcass, flush the vavles once a week and then switch down the road if you want to use a synthetic.
Also a word of caution. Stuff like Zaja Blue whcih has teflon additives will fool you into thinking you do not need to oil your vavles. It is like teflon coating the inside of your car engine and running it without oil. yeah it will work but it is not suggested and it will break down at some point. So no matter what product you use, I would make sure to oil your vavles daily. My vavle set is from 1976 and they are still perfect. Synthetic oil has never touched them either.
Ahhh - It's probably the car nut in me...
-marc