I don’t know about coffewood either

. It seems to be safe for dogs as dog chews can be made of it so I would think that is ok.
@Daisy might know.
Yes that is an option to start with 6” of bedding but it could be good to have a deeper area in a corner or at one end in case he wants to dig tunnels.
There’s an article in the home page about cafe cleaning - I’ll link it. I realise you live in a hot country but I don’t think that would change cleaning guidance really - the only smelly or unhygienic thing is the pee and that can be spot cleaned out. The article explains about spot cleaning. You should never need to do a deep clean unless there is illness or disease or to use the enclosure for another hamster.
Too much cleaning out is very stressful for hamsters and it’s important some of their bedding and cage items always smell familiar as they scent mark everything.
I tend to do a “third” clean every 4 to 6 months. Ie change the substrate in a third of the cage (the house end where they nest hoard and pee). And even then I replace at least half of the substrate I remove if it’s clean. The rest of the cage should stay clean and dry and you’d rarely need to do another third of it and could spot clean mostly.
The article goes into a lot more detail - about nesting areas and hoards as well.
The one thing that is important - especially with a hot climate - is to freeze hamster food, sprays etc before using them, to avoid outbreaks of bugs or moths that can hatch out in heat. Been there, got the t shirt! Virtually all pet food contains moth eggs which are not visible to the human eye and if it gets warm enough they can hatch out and they can lay 200 eggs a day and it become an infestation in the home.
Freezing the food for a week kills moth eggs and other bugs or mites that might be in the food. The same with hay - freeze for a week.
For wood items you can bake them to kill any eggs or mites that might be inside. 100 degrees centigrade for about 30 to 40 minutes.
Tips on how to clean your hamster cage and avoid causing stress to your hamster. It's best to have plenty of depth of substrate and mainly spot clean your hamster cage. Avoid disturbing your hamster's nest and hoard.
www.thehamsterforum.com
It’s still important to try and leave the hamster’s hoard in tact but you don’t want to be leaving a huge hoard in there indefinitely as the older food could go a bit musty. So I tend to remove the bottom half of the hoard, from underneath, when doing the “third” end of the cage clean- the area where they nest and hoard. Kind of prune the hoard.
If the hoard gets pee’d on it does need removing and then you need to put a handful of new food back to replace it, in the same place - otherwise the hamster can get into a cycle of peeing in their food to deter people from stealing it! They get very anxious if they have no hoard at all as they’re hard wired to have food stores.
I have never had to remove a hamster’s nest - unless it’s pee’d in. They tend to keep that very clean and dry. Younger hansters might pee in the best for a while until they get into good habits!
If you put a corner litter tray in the enclosure with sand in it (or inside the house if it’s big enough) the hamster will almost always use it and then it’s very easy - you just empty the litter tray every few days and the cage stays clean and dry. Syrians almost always use a litter tray - if you put it in the right place! Ie the place they have decided to use as a toilet. Sometimes this is a corner of the enclosure. So when you find out where his toilet is you could put a litter tray there.
One good option is to make a large cardboard shoe box house and put the litter tray instead it - they always seem to use it if it’s inside a house - like an en-suite bathroom!