Public transport across route of Cowal Way

[jili]

Hi everyone,
Wondered if anyone can help with some info:
Hoping to do the Cowal Way as part of a group, not all of whom will attempt, or complete the route. Looking to rent a cottage somewhere midway, say Strachur, and travel back from each stage of the route as we complete it, then back to start the next stage next morning.  I don't want to use two cars, one at each end, and wondered if is possible to do this using local bus services.
Any info welcomed, thanks,
Jili