How often should the Baby-Vac be used?

As often as the child snuffles or his/her nose needs to be blown.

Is the procedure sterile enough?

The Baby-Vac doesn't need to be sterile. It's enough to sterilize the evacuator (A) by putting it into boiling water occasionally. If you use it continually it's enough to wash the whole apparatus …

The device is tested by internationally recognized bodies