I haven't had a chance to try this one. I promised myself I had to use up my first Arko puck (to make sure I actually liked wet shaving!) before I bought too many accessories.
HOWEVER I'm really excited about this one, and it's at the top of my list: MÜHLE SHAVE CARE Sea Buckthorn Shaving Soap 65g https://smile.amazon.com/dp/B001QTDG28/ref=cm_sw_r_cp_api_i_830SQW4NQE1VT83S9CG9?_encoding=UTF8&psc=1
Of course if you buy from Amazon, there's a chance it comes in a plastic bag (though that usually only happens for me with clothing). It appears as though there's no extra packaging, just a cardboard box. I'm really excited about the Sanddorn/Sea Buckthorn scent, because it reminds me of my time in Germany. I think it must be expensive, because it's only used in somewhat high end products. At any rate, I know it will smell amazing.
There are two package-free/low waste stores in my town, and it looks like neither of them have shaving supplies. Maybe I should encourage them to carry shave soap!