It's not OK to not wash your feet. It's very easy to scrub them clean daily. After washing your body use the soapy washcloth to do the top and between the toes, then put the soapy cloth on the shower floor and drag your feet, one at a time of course, across it to scrub the bottom. It will only eat up some seconds of your day. It's very important. You can read about why.
Everything is on the ground you walk - feces/droppings, vomit, urine (human, animal and bird), spittle, oils, dead skin cells, dead animals/insects, viruses, bacteria, and a whole lot more (dirt's not clean). All this nice stuff comes up through your shoes and socks (assuming you even wear them) and adheres to the feet. Since the feet sweat - even on the bottoms (why do you think people wear socks), it makes them nice and sticky - all the better for the gunk to stick to them. If one doesn't wash their feet, all this stuff stays on your feet and follows you into bed at night where, due to tossing and turning (or any movement) it makes its way up to where you lay your head and into your mouth and/or nose. This doesn't even take into account that the feet are a prime breeding place for bacteria and fungi. Proper foot washing can prevent or mitigate foot diseases caused by these little critters.
Gosh - that's something I particularly enjoy - sucking Ari's toes or him sucking mine. Not that it happens that often these days. Always an excellent reason for a shower beforehand.
Only when they're actually dirty, for instance, when I've been out gardening. But I do wash and dry every day between the toes. In a hot climate, one must - to prevent sweat and dead skin cells creating a nice environment for tinea.
Kittigate 