Actually both good ideas, I usually scrape mine to get heavy stuff off, the reuse about 3-4 times, then put them in the dishwasher. About once a year I will take them to the car wash but not sure why. I have started using the heavy aluminum pan covers (2) to foil the bottom and I get at least 3 uses out of them, sometimes 4. Having the real estate of a #4 allows me to use a inside drip pan as well. Got that trick from Super Dave if I remember correctly.