Progold prolink is good, it's what I use but you can't mix with anything else or it's gross so I don't put it on customers bikes, but once you've used it to wash out all the old lube it's nice and easy and clean. You can use it to clean and lube, so once it's on you can just top up and wipe down. I'm guessing if it's mostly mud you'll want to wipe that off first. If I go on a few days ride I'll take some in a little soy sauce fish or similar.
Progold prolink is good, it's what I use but you can't mix with anything else or it's gross so I don't put it on customers bikes, but once you've used it to wash out all the old lube it's nice and easy and clean. You can use it to clean and lube, so once it's on you can just top up and wipe down. I'm guessing if it's mostly mud you'll want to wipe that off first. If I go on a few days ride I'll take some in a little soy sauce fish or similar.