Perhaps it's not for me to answer, but seeing other men have, I venture forth. By "new soap", do you mean a new brand, or a new bar of the same brand? Perhaps the composition of the soap does not quite suit your skin in those parts, or perhaps gets trapped in the hair and doesn't wash off as easily, causing the itch. An examination in a little privacy might reveal the cause. Check very thoroughly for an allergy rash down there, or ask you SO to do it for you.
This post was edited by Benedict Arnold at October 21, 2016 11:33 AM MDT
Men don't bother using more than one kind of soap, except shampoo. Hair is rather sad when washed with hand soap. But jock itch is a fact of life for an active male. They use corn starch.
It's interesting in that I've always heard this. However, I heard a dermatologist say that corn starch should never be used on a fungal or yeast infection as it feeds the fungus. I think the term jock itch can mean a real infection where corn starch wouldn't be recommended, or simply a heat rash where corn starch would be a way to relieve symptoms. For the real fungal infection something like Zeasorb powder.
There's always somebody who wants it to be more complicated. The term 'jock' is derived from an athletic supporter first marketed by the Jockey Company about 1920. It is a badge of office among high school athletes. It is called a jockey strap, and that is why all athletes are called jock strappers, or just jocks. And they all use corn starch when the jock strap chafes the skin.