x for y category

I think I have solved it but adding each threshold instead of saying “make every 6th item free from the category” seems a bit stupid.
Is there a better way?
This is what I have so far:
https://drive.google.com/file/d/16oehpGo0Tea3DW6x2htC-w9bSlnpFs5g/view?usp=sharing

hi Anthony

We should treat it as “package (5+1)”.
So we must define “Product Filter” and use “Product discount” ( mode “Split”).
Look at example “Set price for each item” in section
https://algolplus.com/plugins/woocommerce-pricing-rules-examples/#package-rules

For your case — check the screenshot https://imgur.com/HFKfYAm
thanks, Alex