I hate sand. Like I really hate sand. I hate sand on the floorboards and in the bed. I hate how sand inexplicably finds its way into sandwiches. (Yet another reason I should give up carbohydrates.) This is unfortunate, as I live on the Northern Beaches of Sydney with a magnificent, but VERY SANDY, beach at my door step.
I thought I had the perfect solution to the problem. An outside shower in the back garden with hot water.

These fittings are Perrin and Rowe in a satin brass finish from The English Tapware Company. They have developed a beautiful golden patina over a few years. Brass and seriously marine grade stainless steel are the only outside fixtures that won’t rapidly rust if you live by the beach. The taps’ standard finish is white porcelain, but you can match them to your chosen metal finish, as I have done here. All the details and another outside shower layout are here: https://www.englishtapware.com.au/products/OUTDOOR-SHOWER-LAYOUT-11A/
However, my problem was not solved. It appears that nobody under the age of 18 will take the extra two seconds to walk to the outside shower to rinse their feet after heading home from the beach. This is despite whatever level of nagging might take place. I am speaking from experience here.
A better solution (or additional layer of protection) would be to place an oversized clam shell or a small Chinese porcelain goldfish bowl filled with water right beside the backdoor. You might then be in with a running chance of a house without sand.

Giant clams are classified as a vulnerable species, but you can increase your mortgage to buy an antique shell. Otherwise, source one of the excellent resin ones (https://pineappletraders.com.au/collections/resin-clam-shells/products/vintage-polyresin-clam) or one of the fabulous sculptures that are available (https://www.etsy.com/shop/TeeMorrisShells?ref=search_shop_redirect).
You will see various examples of both real and replica giant clam shells repurposed as bathroom or powder room sinks. Please avoid this path. Please.

Chinese porcelain goldfish bowls are readily available very cheaply online or head to China Town in your local city. We are not sourcing anything Ming Dynasty here.
Mosquitoes breeding in the water are not an issue, as you need to rinse the shell or bowl regularly. To remove the sand. You could add goldfish to be certain (they eat the mosquito larvae), but I think that would discourage the foot washing, and you’ll be back to sand tracked through the house….