Hello. Well Syrians are bigger so there's more wee! But they're usually quite clean and tidy if you give them a litter tray to pee in - then you only need to empty the litter tray
Syrians usually choose one place as a toilet (and don't pee all over the place - although they can pee in their wheels as well). It's often a corner of the cage. So if you know where she pee's, pop a corner litter tray there with chinchilla sand in it and she'll use it. Then you just empty the litter tray once or twice a week.
We had a rescue syrian a while back and he was in better habits than most hamsters! Very tidy! With his pee area well away from his nest - I think he was institutionalised!
It's unusual for an adult syrian to still pee in the nest though and their nest area usually stays clean and dry. In fact their pee is the only smelly thing really as they are quite clean generally. Having said that, female syrians come on heat every four days and can, apparently, have quite a strong musky smell. Some smell more than others and some people notice it more than others. If it's that then a small air purifier in the room will solve it!
If it's just a pee smell then there are things to do with set up that can make it less of an issue. Firstly the toilet, but also having a good depth of substrate and a good sized house/nesting box that's open underneath and sat directly on the substrate. This encourages them to have normal behaviours. They burrow down a bit, bury hoards under their nest and the house stays more ventilated being directly on the paper substrate.
The old way of minimal substrate and cleaning out a lot makes things worse. If they're cleaned out a lot, it removes all their scent so they pee even more to scent mark everything and claim it as their territory.
Not sure what your cleaning regime is but I find with 4 to 6" of substrate, a large house and a litter tray, the whole cage stays clean and dry and you just empty the toilet as and when needed, wash it out and replace the sand.
In terms of cage cleaning, best to do "partial" cleans. So don't clean everything at the same time as you change the substrate - maybe do wheel a different week and any other items a different week again. With 4 to 6" substrate also you can just "spot clean" now and then - it take out the odd handful and replace it with a clean handful and mix it in. Doing that you can easily go 2 or 3 months without needing to change the substrate (providing there's a litter tray). Even then I only replace half the substrate and keep the clean half and mix it in so it still smells familiar (the bottom half is usually clean and dry). that might sound expensive on substrate but although you need a lot to fill the cage, in the long run you end up using less.
So I don't think of substrate as something to minimise smells. Kaytee clean and cosy on here is very popular and so is Fitch (both paper based). Kaytee C&C is better than Carefresh IMO because it has less dust. My favourite is Fitch because it's just recycled food grade paper and completely dust free. Hamsters also love it and take bits for their nest, and it keeps it's shape well if they dig.
House wise, a shoebox is a good size for a nesting box for a large cosy nest. Everything is bigger with syrians! Bigger nest, bigger toys needed! Most hamster toys and houses are only for dwarf hamsters. Syrians are better with rat sized toys and tunnels etc.
This is the litter tray I get
https://www.amazon.co.uk/Trixie-Corn...401893&sr=8-25
Some people have found Carefresh itself can have a funny smell! Porton Aquapet sell Kaytee Clean and Cosy. Fitch is only sold by the manufacturers and sold in bulk, so I find works out very economical.
Whatever you do don't buy any bedding that says "enhanced odour control" or something like that - these contain things that are harmful for hamsters or can cause allergy. Just get the plain Kaytee C&C if you go for that - they do it in white or natural. Fitch only comes in white
But you get used to it lol. At least it shows up the pee and poops!
Kaytee C&C - the white comes in the biggest bag
Kaytee Clean & Cozy White 85L | Welcome to Porton Garden Aquatic & Pets
Natural
Kaytee Clean & Cozy Natural 49.2L | Welcome to Porton Garden Aquatic & Pets
Fitch - only availble online
I get the 10kg bale which lasts at least 6 months with a 100cm cage. It's quite bulky but not too huge. They do it in smaller compressed bales as well now. Not so economical that way. Your dwarfies might like it too.
Fitch First - Fitch Paper 10kg Single Bale Bedding For Smaller Critters
Fitch First - Fitch First Paper Pet Bedding