Whichever one has no warnings in ToxFox¹. I am partial to Schwarzkopf’s Nature Box line but I’m the end I’m not picky as long as there’s no nasty shit in there.
¹Explanation for non-Germans: ToxFox is a mobile app released by German eco-NGO BUND. It lets you scan a cosmetic product’s barcode to look it up in an ingredients database. It will show warnings if the product contains stuff like microplastics or ingredients that aren’t entirely harmless.
Depends on your keyboard layout. On Macintosh-like keyboards it can be as simple as AltGr+dash. On smartphone keyboards you can just long-press the dash.
On Windows you’re expected to hold down Alt and enter some code.