I have never heard that zinc helps acne per se. If you eat meat, you probably get enough zinc already. I would not take more than 15mg day unless a doctor told you to do so.
You can make your own aspirin masks easily and cheaply:
Plain Yogurt ~ Table Spoon
Uncoated Aspirin (coated will also work but it takes longer to break down) ~ 10
Fresh squeezed lemon juice ~ however much your comfortable with, basically enough to thin out the mixture a little but not make it soupy
I've recently added the witch hazel to the rotation and am seeing good results with Thayers Unsented. My zinc comes from a powerful multi-vitamin.
Zinc is good for many things and taking a zinc supplement will certainly not hurt you. It helps support testosterone production, and aids in overall healing.
It depends on your age and body chemistry. As a Teenager my Indian Great Grandma took one look at my skin and put me on Zinc my face cleared up in a week and I took it till I was about 21.