Hi Picard.
If you have washed your feet thoroughly and your feet are still wiffy then you may well have a toenail fungal infection.
Where toenails are discoloured brittle and hard to cut.
You will therefore need something like Curanail
http://www.curanail.co.uk/what-is-a-fungal-nail-infection.html?gclid=CK_k6d_q9pICFQVrMAod-V6vBQToenails are painted every week and the infected nail then grows out without spreading the infection.
Athletes foot (again another fungal infection) can be cured by a strict washing routine, especially between the toes using soap containing Tea Tree oil or Bog Myrtle together with an appropriate medicated foot powder and by wearing either pure woolen or X-static Socks and leather shoes rather than shoes made from synthetic materials. And always use flip flops in the local gym or public bathing areas to prevent re-infection.
If your toes look like this
Then you should seek medical attention.