@Carmanah0 There is no standard etiquette for how much cleaning a guest is expected to do. Various hosts have different expectations.
Those expectations, to be fair to the guest, should really be made clear at the outset, but some hosts may think it's enough to just mention it when you arrive, if it simply consists of basic respect in cleaning up after yourself in shared spaces, or running the vacuum around on a "take turns" cleaning basis. Also a host may not expect much in the way of cleaning for a guest who only stays for 2 nights, but a guest who stays for 7 weeks is more like a roommate and it seems reasonable for them to share some responsibility in cleaning.
Cleaning fees are one-time only fees. You can think of it as either making sure everything is clean for your arrival, or doing a major clean of your private space after you leave.
It seems reasonable to me for a long stay guest to do a fair share of keeping the place clean- sweeping, vacuuming, wiping down surfaces, taking out the garbage, making sure the stovetop isn't swimming in food and grease, etc.
However, major deep cleaning chores like washing the windows, cleaning the oven if you yourself haven't used it, scrubbing out garbage cans, moving furniture or appliances around to clean under and behind, that sort of thing, don't seem to me to be a reasonable expectation for guests.