What is the fastest and easiest way to clean dust buildup from interior log home walls and beams? Any cleaning product suggestions?

I would try using a vacuum cleaner (cannister type) with a brush attachment. That's what I use to clean my wooden blinds. A heavy duty shop vac would work excellent also.

A leaf blower.

A leaf blower?? Inside a house? That's silly - it will blow the dust everywhere.

KBC was just kidding but you did ask for the fastest and easiest. A shop vac with extension tubes and a brush nozzel should do it. After 7 years of doing this I finally put some polyurathane on the logs. They still get dusty but clean more easily.

I know KBC was just kidding and I had a good laugh because I could picture a guy cleaning that way :D - sorry for the stereotype.