You should not be getting a saddle sore, or having trouble with saddle friction on rides under a century! If you are, there is something wrong, or you've been unlucky with the weather.
These are the causes of problems on shorter rides:
1. Your bicycle is incorrectly set up (saddle too high, saddle too low, saddle tilted wrong). If it is too low, you'll rub more and have more friction. If it is too high, you'll rock.
2. You've got the wrong saddle - those gel things or any kind of saddle where you sink into soft cushioning cause more friction. I went to a Brooks saddle with great results.
3. Your shorts are too loose. If they are loose they travel and that causes friction. I have trouble when my shorts have reached their 2-year mark, and what a HUGE difference a new, snug, pair of shorts makes. I do not wear a pair of shorts that is more than 2 years old on long rides.
4. You've got the wrong shorts. After my previous shorts started giving me trouble I went shorts hunting and was appalled by the number of shorts that had their chamois seams right across my sitbones (and I don't have wide hips!). Like I want to be sitting on seams for 24+ hours!! I bought the one and only pair with a chamois that covered my sitbones.
5. You ride in wet weather - if you ride any sort of distance in rain, you want some sort cream (I'll get to that in a minute) on your friction points. Your skin is more sensitive and fragile in wet weather.
6. You ride in hot weather - same sort of thing as riding in wet weather except the moisture is not created by rain, but rather by sweat.
7. You forget to use your cream on a ride of 100 miles or more (unless it's hot and wet, you shouldn't need it for rides less than 100 miles).
8. You don't shower and clean yourself well right after the ride, or depending on the length of the ride, a few times in the middle of the ride.
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There are various products you can use if you are caught in the rain, or if it is very hot such as Bag Balm, Chamois Buttr, and my favorite Johnson's and Johnson's Daily Protection cream.
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And as for what to do if you get a saddle sore ... apply zinc. Get ahold of Johnson's and Johnson's Diaper Rash Ointment (with zinc) or something similar with a high zinc content and apply liberally before going to bed at night. In the morning everything will be OK.
If for some reason it is not gone by morning. Have it seen to by a Dr. It is either something else or is much worse and much more serious than I've ever encountered in all my miles of cycling.