That's why my 'one watch collection watch' would have to be on a bracelet. In terms of taking care of the leather, I highly recommend gentleman shoes-related channels on YT - they really care for their high-end shoes :) I picked up a few tips from them, that can be applied to both shoes and watch straps. The first and most important is Saphir Renovateur Creme - expensive but I didn't manage to exhaust the first jar for like 5 years now :) (a little goes a long way with that one). I didn't find any reasonable method to deal with sweat, other than solutions that might be good for shoes, but don't feel right for a delicate strap (e.g. rubbing alcohol, hydrogen peroxide). If that's a raw leather it might be ok, but if it has a delicate lining on the inside (most of the dressier watches go for that arrangement), it feels a bit 'meh' - but I will give it a go, I have a few straps that are on their last legs, so I might just as well sacrifice those.