Why not ask them which Monday the text refers to either before or when you submit the form? That way you know exactly when the inspection will happen and don't have to agonised stress about which Monday they are referring to.

Is it perhaps worth looking around for local professional cleaning companies and getting a few to give you quotes for carrying out a deep clean of your apartment prior to the inspection (once you know when the inspection will be carried out)? If you really expect them to screw you over for cleaning charges then it may work out much cheaper to have a cleaning firm come in and carry out a thorough clean of the whole apartment.

Even if it wasn't cheap, it would save you having to try to do it all and you wouldn't have to endure the stress of worrying about whether you had done a good enough job (or whether you were even going to manage it at all). Even if you did manage to do the full clean yourself, its going to leave you ruined for days and days so its got to be worth at least looking into it and weighing up the cost versus the benefits to you and your husband of (a) not having to do the clean yourselves plus (b) not having all the added stress of doing the clean yourselves.

Not only that, if the Apartment Company then try to screw you over for cleaning charges, you can dispute them on the basis that you had a professional cleaning company in to carry out a full, deep clean. If they give you a written quote and receipt detailing all the work they have carried out then it will be very hard for the Apartment Company to try and charge you.

Just some thoughts - felt free to ignore if they aren't helpful.