Joined: Mar 2014
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From: ,location, location
Bikes: Foundry Chilkoot Ti W/Ultegra Di2, Salsa Timberjack Ti, Cinelli Mash Work RandoCross Fun Time Machine, 1x9 XT Parts Hybrid, Co-Motion Cascadia, Specialized Langster, Phil Wood Apple VeloXS Frame (w/DA 7400), R+M Supercharger2 Rohloff, Habanero Ti 26
I would try using DZ Nuts or maybe my favorite Chamois Glide. I would also make sure my position on the bike is good and my saddle is the right size and shape for me. I am doubtful the shorts would be an issue, it is possible but very unlikely.
One final thing that I recommend as well is showering off before you bathe. I don't think the bath is the cause of problems at least from what you said but washing off the sweat and bacteria is always a good thing so you aren't bathing in it!