Reddit reviews Weber 7444 22-1/2-Inch One-Touch Cleaning System Kit for Grills,Silver

The build-up looks like carbon to me. It can be scraped off without much trouble.

I just did a rehab on my Weber Kettle after 10 years of continuous service (and 10 years of sitting outside uncovered in Michigan winters). You can easily spend as much on replacement bits as the cost of a new Kettle, but I like to keep my gear in good working order.

Here are some bits you can buy if they need to be replaced:

Lid handle: https://www.amazon.com/gp/product/B000WEOOWO/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Charcoal grate (the bottom one): https://www.amazon.com/gp/product/B000WEKNMY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Ash Catcher: https://www.amazon.com/gp/product/B000WEOQ1I/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Ash Clean-Out Fins: https://www.amazon.com/gp/product/B005LVAZ3A/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Body Handle (with tool notches): https://www.amazon.com/gp/product/B00FDOOQD0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Hinged Cooking Grate w/ BBQ System Doodley: https://www.amazon.com/gp/product/B0044EQM9Q/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Here are a couple other components that I swear by (and will save you time and money):

Charcoal Chimney: https://www.amazon.com/gp/product/B000WEOQV8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Charcoal Basket: https://www.amazon.com/gp/product/B000WEMGM4/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Good luck!