We treat our grays with a little of the same chemical for the black....add a little water just like the black....never had an issue with smells on any of them.
Lloyd & Kathy & Kit(17 yr old cat)
2014 Forest River Cedar Creek Silverback 33RL
2016 Chevy 3500HD Z71 LTZ 4WD Crew Cab, DuraMax/Allison.
2014 - 38 nights/3500 mi.
2015 - 66 nights/6260 mi.
2016 - 33 nights/4707 mi.