The cages around here are cleaned every week. The regimen is that the snake is put into a temporary holding cage, the newspaper (that's what I use as a substrate) is rolled up and thrown away. Any loose fecal material is scraped from the bottom of the cage and deposited into the 'scum bucket'. These buckets get dumped on the bamboo groves whenever they get ripe.
Fresh paper is put down, the water bowl wiped out and fresh water provided. The snake is then put back into it's cage and offered a meal.
Now a well acclimated corn snake will not get stressed out from this sort of activity. It will be just part of the background scenery for it, and as long as it has no fear of you, there is no need to get stressed out. Matter of fact, mine are SO used to this procedure that they have learned that they are going to get fed sometime in all of this activity and it is sometimes a challenge keeping the snake from grabbing your hand by mistake. One the hatchlings get to be about a 6 months old, they have picked up on the routine and are acting the same way.
It is VERY rare for us to have a corn snake act stressed out for any reason related to cage cleaning or handling. I guess this is because 20 some years of weeding out the malcontents has just about eliminated that sort of misbehavior in those guys.