I don't need to do really "clean my bag out" regularly as I deal with things on the spot/on the go. I use purse organizers and pouches to organize everything, so if I get a receipt after a purchase it immediately goes in the pouch or whatever I am using (like a pocket on an organizer) for receipts in that particular bag, if I have change it goes in a coin holder. I won't stand at till and do this, but will do as I walk away or as I get to my car, or whatever. I don't carry "loose" food or things like that in my bags. In other words, I don't end up with loose receipts, change, cash, or so on at bottom of my bag at the end of the day.
I rotate my bags frequently (usually about every 2-5 days, if I am feeling lazy it might be 7 days) so I just shake the prior bag out when I do that before stuffing it and putting it in its dust bags. If it's a light/white bag I will run a leather cleaner wipe over it before putting it away. Others I clean and condition the leather as needed (if I see a mark) and whether needed or not will do it for all my bags (minus my canvas of course) a couple times a year as well as protect those that need it. I rotate my work totes less frequently, maybe every 2-3 weeks, but all the same applies as above.