There’s also this spray you can put on stuff after you wash them and they are damp, it’s likenwhat they put on windbreaker jackets to make them water proof or tents. Probably full of pfa’s now that I think about it though

There are diy versions that combine paraffin and linseed oil, or just paraffin.

You can do the same thing with paraffin wax and mineral oil, it’s just less “natural”