Indeed it can be done in 28.
Tool: flip the top edges and the bottom edges:

	(R L) (U D) (F B) (R L) (U D) (F  B) 
					/\
					||
To do the other four, insert the following things at the indicated
place
	(u b') (u' D b' u' d l' u' d f' u' d r') (b u')

There may be another place to put this to find a shorter path.
Those with time are free to try and find one.