I have a kitchen fume hood which has a reusable mesh filter. This is now clogged up with grease and has 7 layers of mesh I am not going to attempt to dismantle it as it will be big problem putting it back together. So far I have used the following attempt to get rid of this grease.
1) Cillit Bang
2) Pressure washer
3) Grease lighting (did a good job but still a lot left)
4) Boiling hot water
5) fairy liquid soaked over night
get the Oven Pride oven cleaner and put the whole mesh section into the bag provided for oven racks. Leave overnight and then rinse off. Should come out like new.
I think it is called 'Oven Pride' where you usually soak your oven shelf racks for a period of time and it gets all the black off. Wilkinson do their own brand version.
You put whatever in the plastic bag add the fluid and shake it periodically until all the grease and grunge is removed. I usually leave mine overnight works a treat.