Hi does anyone know if this is available here, or what a local alternative may be ? Its for chickens & coops .

It is available here in either food grade or agricultural grade.
it is called diatomaföld or kovaföld
google it
e.g
Diatomaföld DE szűrőkbe (20 kg)

Also used here is alganite https://en.wikipedia.org/wiki/Alginite it is mined in Pula https://www.mineralholding.hu/iparia.../alginite.htmld and is a very useful addition to chicken poo prior to use (also cat litter and in the chicken house to reduce smells) and as water retaining fertiliser for the garden

Thank you Peter, have read is is good for chickens & prevention of mites etc.

It also is a good repellent for fleas on cats and dogs