falling off my flip-flops

I wear flip-flops when I water my yard. It makes no sense to wear fancy shoes, or shoes that are difficult to put on or take off since I come inside for the half-hour needed for each section of my lawn. I have sprinklers in one small area of my backyard, so I do manual labor to get water to the rest of the thirsty little blades of grass. But I digress. So, there I am in my flip-flops turning on the sprinkler or moving it to a new area and I always get wet, especially my feet. I set the sprinkler and walk away. I haven't gone more than three steps when my feet go slip-sliding away on my flip-flops (we used to call these items thongs when I was growing up, but if I talk about my thongs slipping, some people would get the wrong image and idea and we do not want that happening). It must be the foot cream I use to keep my feet from looking as old as they are. The water hits my feet, the lotion becomes slime and my feet go sliding. I begin to totter and teeter and I resemble a drunk who is in need of a major sleep-off. I then have to make a decision--go barefoot and risk stepping on a snail and feeling the crunch/squish directly or keep the flip-flops on and risk breaking my neck. The snails lose. The flip-flops come off and I am once again able to walk like the sober human being I am. I've tried several different slip-on style sandals and flip-flops, but they all have slick inner soles. My question is--why would anyone create a slick, slippery inner-sole for a shoe being worn around the water--beach, pool, lake, etc. by a person who will be getting wet and will probably be wearing sunscreen lotion on his/her feet. Someone at Sandals R Us is laughing and probably buying stock in medical insurance.