You needn't worry about that: If you put your pocketbook down, it will stick to the floor like glue. If it's a cheap theater, the urine smell drives most of the creeps off anyway.
I always keep my pocketbook on my lap. But I see so many stupid people putting theirs on the ground.
Here in Huntington, NY we had a rash of thieves stealing pocketbooks left on the ground.
No matter where I am, my pocketbook is ALWAYS as close to my body as physics can allow. And I will fight for it.