I use preventive cleaning in all my units by lining the base with HD foil.
Depending on usage I replace as warranted. On my offset its after each
smoke because I get alot of spill-over from my drip pan.
On my gas vertical, my pans catch most of the drippings and probably replace once a month. I coat my burner with vegetable oil about twice a month and air hose the burner cavity also about twice a month.
I also clean my grates after each smoke by putting them in the diswasher
with the addition of 'Barkeepers friend', I knock off any of the larger chunks
and let the washer do the work.
In my opinion, it prolongs the units serviceability, keeps critters, flies and spiders from enjoying the aftermath of one of my smokes. I live in the country and have frequent coon, possum, dogs etc, wanting to investigate
the remaining assortment of enticing aromas.
I never have an end of season as I will smoke year round and it really has to be nasty-nasty for me not to smoke something every week. So its clean for me and keeping fresh foil aids the clean-up easily.
Jack~