If you have a patio mat that has tiny holes in it then it won't catch a lot of sand. The best way to keep it all outside is to remove your shoes which also helps when walking on blacktop to keep black marks off. Adjust your windows if you have them open - close off the ones that the wind is blowing from and no need to leave them wide open. By adjusting them directionally and turning on a ceiling fan like a Fantastic and having a window covering on the sunny side, you can keep a cool RV without having all the windows wide open.