So, I've found that my cat's silicone food mat makes a great handgun cleaning mat. The edges are raised to contain any parts or fluids from running off.
The large one is just the right size for handguns. I would think the XXL would be ok for an AR taken apart.

https://www.amazon.com/gp/prod...03_s00?ie=UTF8&psc=1

Sweet!
And reasonable priced
Even better than what I was going to suggest

https://www.amazon.com/gp/aw/d...s_sparkle_scm_asin_1

I have a smaller one of these for pistols. I want this one for long guns.
[URL=Lyman Essential Heavy Duty Gun Cleaning, Maintenance Mat 10"x 36" https://www.amazon.com/dp/B01C...ing=UTF8&psc=1]Lyman Rifle mat[/URL]

Disposable yoga mats. Cut to fit....