LCR (Liquid Creosote Remover) 5/8 Mesh You could use a vacuum

You could use a vacuum to clean them but a less time consuming method is to use the smoke shelf scraper to pull the ash down and shovel it into a container

The crossbars aren't welded in on this chimney cap

And of course

Smoke Guards are spring loaded for placement while the silicone adhesive sets

The Universal Copper Cap's mesh and hardware are copper clad 304 Stainless Steel

LCR (Liquid Creosote Remover) 5/8 Mesh You could use a vacuumLCR is a liquid advanced solution specially formulated to remove third degree (stage) glazed creosote from chimney flues without the need to add water thus reducing exposure to toxic dust It penetrates, dissolves, and absorbs the creosote buildup, causing it to lose adhesion and detach from the flue surface as it dries making it easily removed during a standard chimney cleaning. For use on Stainless Steel, Masonry or Ceramic chimneys.