I manage by having mainly after school children - 7 after school children ranging in age from 4 - 11. And I only have one 3 year old two days a week (7.30-6).
I have two DC's (4 & 7) DS2 (4) goes to nursery 5 mornings and I get things done then when I'm not working.
But on the two days I work I make sure I do bits a bobs
e.g. Load washer and hang out.
Load and unload washer.
Declutter kitchen work tops.
Nip washing up stairs on a toilet run. Quickly pop stuff into rooms whilst 3 yr old mindee is on the loo and run a sink of water for him to play in wash his hands in, and get a bit more tidying done/ beds made. (2 min job)
I keep a pack of surface wipes handy in my playroom for a spot of wiping up when necessary.
I set them off on a task and get cleaned up after meals and wipe down surfaces and doors and wipe away muck as I see it.
I spot clean toys when the kids are there.
I vacuum every couple of days depending on the messiness. But get the Dyson out if needs be during the working day as it get traipsed through the house if not.
I make the children even my youngest takes their pots to the sink. And get the older ones to pour and give out drinks. (they love the responsibility)
I make the children clear away the toys periodically so that everything is not out at once and so I'm not left with a big mess when they all leave at different times.
When I know their departure time I make sure they've tidied up and are sitting quietly waiting for their parents about ten minutes before pick up time.
I do my shopping online as its one less job to run around doing. (done on an evening and added to my iPhone as and when I think of stuff)
I do my EYFS paperwork in an afternoon whilst my DS and mindee play, so I can send home his journal.
But I only have 1 plus my DS (and they aren't young ones). Not sure how I'd cope with 2 younger ones.
I don't think it hurts for them to see you doing chores and be unavailable for short periods as its like being at home. And I also think it's important to have a clean, tidy and organised home when minding and it is necessary to keep on top of stuff during the day.
My mindee has been dusting the stairs today! 