How often to replace media in a brass cleaning tumbler

I think it was five or six years ago that I bought a "Thumler

Wet Tumbling Brass with the Lyman Cyclone - The Armory Life

Wet tumbled with stainless steel pins. What the hell did I do

Corn Cob Media (untreated)

Brass Cleaning with Stainless Media within

How Long Will Walnut and Corn Cob Media Last?

Brass Cleaning with Stainless Media within

Vibe tumbler media options

What's The Best Way To Clean Brass?

Cleaning brass- stainless steel media, dry media or ultrasonic

Vibratory Case Cleaners Vs Wet Case Tumblers

Wet Tumbling Brass vs Dry Tumbling Brass: What's the Difference?