I always had a problem with my neighbor's cats snooping around in my backyard and I can't leave my garage door open unsupervised cause they'll wreak havoc in there. Since I have a gravel yard, I'd just huck rocks at them and they'd run off. One found out I have no aim, so the rocks stopped scaring him off. Super, right?
When I gave up on rocks, I looked into different remedies and found out cats hate Cayenne pepper. So I put cayenne pepper all over my wall and yard and even on parts of my vehicles. Now, the only time I see cats is after it rains, but I have a huge canister of cayenne pepper and can re-apply anytime!
You may find creative ways to spread some cayenne pepper in your layout room. You can also get the powder and mix it with water in a spray bottle. No .22 caliber needed. Just "pepper" them with some water if they set paw in the layout room.