Use the best anti spatter spray ever, I will give you a hint....Its edible, cheap, and comes in a colorful spray can.
Spatter built up inside the mig nozzle eventually will arc out between the nozzle and contact tip. When that happens, the arc sputters. When the arc sputters, you start monkeying with the mig setting. All the while it was just spatter arcing inside the nozzle. I have tried a few anti spatter sprays and they all had warning labels that they caused cancer and other bad stuff.
So why not just use something that works with not hazardous chemicals.
Want to know what it is???
Its safe, and It works great.......