For the merino and lycra and stuff, I just use a very mild non-bio. I now only own 1 HH-esque poly-propelene top which I have to hot wash with nasty detergent to get clean, and even then it's a bit smelly.
Base-layers for more than 2 days... never been touring, or camping?! 5 days in my merino top on a climbing trip was the longest between washes - despite lots of physical exertion and sleeping in it, it was still passable* at the end. Long lasting thermals are a real bonus, because you only have to buy a couple to see you good.
For the merino and lycra and stuff, I just use a very mild non-bio. I now only own 1 HH-esque poly-propelene top which I have to hot wash with nasty detergent to get clean, and even then it's a bit smelly.
Base-layers for more than 2 days... never been touring, or camping?! 5 days in my merino top on a climbing trip was the longest between washes - despite lots of physical exertion and sleeping in it, it was still passable* at the end. Long lasting thermals are a real bonus, because you only have to buy a couple to see you good.
(*at least relative to the rest of me!)