I concur that this is more for touring than LD. Only the most epic LD events go for a week straight.

The real key is to avoid developing the sores to begin with. Keep in mind that you get saddle sores from a combination of chafing and bacteria. So I'd do the following:

• start using bag balm or bodyglide
• consider replacing your shorts; if you've had them for a long time, you may not be able to ever get them clean enough, or they may not be working for you
• get ridiculously scrupulous about keeping yourself clean
• shower as quickly as possible after the day's ride
• do not wear your bike shorts a minute more than is necessary; change into something clean as soon as possible