From 3 to 5 days:
on a paper towel (sopalin, newspaper) in an airtight container in refrigerator.
Up to 10 days:

The brush carefully in tap water, dry them and put them in a container, cover with oil (olive or other). You can use this fragrance oil for your salads or other dishes.

Several months:
Once washed, dried, freeze truffles, vacuum or directly into an airtight packaging to preserve the scent.

To sterilization at 100 degrees.
For 40g truffles: 2h.
For 40 to 100g of truffles: 3h.