Usually the smell will disappear over time. I once put some rubber sound proofing in an old car and it did smell initially, but became unnoticeable.

Personally I am wary of jet/pressure washing anything containing rubber.

I used to pressure wash rubber (and carpet) mats all the time in a previous life as a car valeter, never experienced any negative effects.

But I doubt doing so would have any effects on the smell of new mats