Wattyl stain blocker
2 cans 4L Wattyl spirit-based stain blocker never opened. We purchased these when we were going to paint over the ceilings in our house where the previous owner was a smoker. In the end we replaced the ceilings because we found out the electrics had to be redone as well. Cost over $100 per can from Wattyl. https://wattyl.com.au/product/master-prep-spirit-based-stain-blocker/