Set up your round geographically in a sensible route*. If necessary, spend a couple of days with a map and plan a route.
Then effectively you drive round the route every 4 weeks, over the 4 weeks. If there's a street with a mix of customers, you just do the ones that are due. Every other time, you're missing your 8-weekly customers. If you take a week off, everybody is done a week late. Each day starts where you broke off yesterday. Within that general rule you also know who wants a 7.45 clean and who has asked you only to be there in the afternoon, but the principle still holds.
It's simple, effective and minimises your mileage. I do 3,000 miles a year nowadays.
Vin
* I assume CleanerPlanner will allow you to do this. If not, dump it and go to Aworka. Don't let software restrictions drive how you run your business.