When I was a Webelos Den Leader, a majority of the committe consisted of parents of my Webelos (or cubs in earlier years). We really worked our tails off and every year, the committee kept getting smaller and smaller as the years wen ton and parents of the older kids left. When our kids were Webelos IIs, we saw the potential storm on the horizon of all the active adult leaders moving on to Boy Scouts leaving a Pack to dissolve if we didn't start recruiting.
We decided to have a Scout outing in a neighborhood pool with lifeguards. We decided to have a committee meeting at the pool party to go over issues, but more importantly, to explain to parents that are at meeting but don't do anything that we need help with certain manageable tasks. It actually worked and we recruited some parents that became regular. It turns out that as our committee dwindled in size, the parents saw what all that we were doing and were fearful of committing to help becuase it looked like alot of time to dedicate. We just asked them to handle certain things, like one to organize the Blue and Gold and one to organize the Pinewood Derby, etc. Before we knew it, a committee formed.