@Josephine266
I now only host long term stays (mostly one month+) but, previously, yes I would offer to clean a guest's room/change linens and towels half way through a two week stay (make sure to supply enough towels to last until then). Most guests seemed very happy with this but some would say it's not necessary.
With my long term guests, I give them the choice of having me do this every couple of weeks, for a small fee, or they can do it themselves and I supply them with extra sets of linens, towels and cleaning materials. The problem with the latter is that a lot of guests say they will do it themselves and then don't.
I don't want to have to throw away bedlinens because the guests let them get too grubby or to find nasty surprises in the room after the guest checks out, so I do encourage guests to opt in for the cleaning by keeping the cost very low. I'd rather have the peace of mind. Failing that, I'll keep an eye on them (easy to do being a homeshare host) and gently remind them if I think they are not washing anything.