Six jours

I think it's worth pointing out that saddle sores and soreness from the saddle aren't necessarily the same thing. A saddle sore is an actual bacterial infection, like a pimple or a boil. Soreness from the saddle is just worn-away skin, caused by friction.

The latter is pretty obvious when it is developing. If you are getting sore from the saddle and notice redness where you contact the saddle, chamois cream (which is valuable primarily as lubrication) can help.

Actual saddle sores, however, usually form inside hair follicles. And it may be that preventing chafing can help prevent them in some people, so it seems logical that chamois cream would always be a good idea. But anything that tends to interfere with skin circulation can actually promote follicular problems - in the old days, when we all used natural chamois, Vaseline had an absolutely poisonous reputation because it could so easily contribute to follicular inflammation. Noxema (and similar) was often used as it was thought to help prevent such maladies. Some people actually mixed over-the-counter antibiotic preparations into their favored chamois cream. Hygiene, of course, is paramount for folks susceptible to saddle sores: never wear the same shorts without washing first, and make sure to thoroughly cleanse your sitting parts immediately after a ride.

The short version, IMO, is that if you don't have a problem you don't have a problem. If chafing becomes an issue, a "designed for cycling" cream may be indicated. And if you start developing actual saddle sores, then you'll need to start putting serious thought into all sorts of things, most of which can be addressed on this website, if need be.