The rust problems from a day of carry can be prevented with Militech-1. I had similar problems with my blued P-3AT on hot summer days. I coated all metal parts of the gun with Militech-1, put them in the toaster oven on 225 for 15 minutes, and let them cool. I repeated this 3x. I never had the problem again. About 6 months later I was doing another gun so I did the Kel-tec again although it probably didn't need it. I have treated about 7 guns so far and used 1/3 of an ounce. A one ounce bottle is probably enough to treat a single carry gun for the next 20 years. As a side benefit the just wipe clean now.
Don't ever set your CCW down anywhere outside of your home or car, period. You are doing nothing but opening the door for major legal problems. Think if you set your gun on a TP dispenser and left. The next person in the stall is a 10 year old who finds the gun and shoots himself playing with it. Guess who is going to prison? Your gun must be kept in your immediate control at all times. It's not really that hard to do. Just flip it inside your pants as others have suggested.
I have a friend who has had his permit longer than me and is one of the most responsible gun owners I know. He couldn't find his CCW for a week. He knew it was in the house but wasn't sure where. It turned up in his basement bathroom which he seldom uses. He had gone in and left it on the counter. Good thing it was in his house but he learned a valuable lesson about setting his gun down.
When I was getting my NY CCW permit the Sheriff doing the class said the record for the shortest length of time before permit revocation in the county was the guy who got it for hunting. The day after he was issued his license, which is NY is expensive, lengthy, and a PITA to get, he was on his way hunting in the morning. He stopped at a convenience store to get a coffee and use the bathroom. He set his nice revolver on the back of the toilet, did his business, and left. A short while later he discovered the gun was missing. He raced back to the store to find the police already there. Someone else had found it and turned it in (lucky). Since NY is a shall issue state the issuing judge decided the guy wasn't responsible enough to have a permit and revoked it.