#1 Cause of excessive oil from crankcase vent hose (aka slobber tube) is overfilling the engine oil crankcase.
Do NOT assume that the engine oil dipstick that came with your coach is accurate-- it was NOT supplied by your engine manufacture.
Determine the correct oil quantity for your engine-- call with your engine serial number:
Cummins: 800 343-7357
Caterpillar: 877 777-3126
And, at the next oil change, CALIBRATE THE ENGINE OIL DIPSTICK.
And, also, do not add oil until the level reaches the ADD mark.
If you do fit a container under the hose, make sure that it does not restrict air flow (i.e. size of outlet is at least as large as inlet and any material you put in it is course enough to not restrict air flow.