@BigOldOakTree
I have been in the hol let business for 25 years, so have seen most degrees of awfulness (and niceness) from guests.
I have had tenants who have left my properties in that sort of state, and I have always deducted the extra cleaning hours from their deposit. The 'cleaning fee' is meant to represent a reasonable three-hour clean. If it takes seven hours, that is my time, and I expect to be paid for it.
I take photos of all mess, damage, etc, in case the guests claim they left the properties in a decent state.
I also withhold the deposit from tenants who go above and beyond the normal 'wear and tear'. So I wouldn't, for instance, bother about a broken wine glass/crockery etc. I wouldn't worry about one wrecked towel (thanks, fake tan). However, I did claim the money from the deposit of one particular tenant who wrecked six towels with hair dye and fake tan (she denied it, but I had the photos of the towels before washing, and after three washes).
Guests can, and will, leave bad reviews if they are aggrieved to have found their own filthiness penalised. However, all the hol let websites enable you to reply to negative feedback - and it will be clear that one random poor review, to which you can reply, is not representative of the service you offer. You can also review the guests.
I don't in fact expect guests to remove all their rubbish. I like it if they do, but it's not an expectation. In some ways, it's easier for me to deal with it, as I know when the rubbish/recycling is collected.
I am satisfied if guests leave the properties in a generally tidy state. I don't expect them to clean anything - just 'generally ok' is fine. I give a five-star review to any guest who doesn't force me to do extra hours of cleaning/moving furniture back to its rightful place/washing up (ugh), etc.