Mercedes cls320 cdi 2006 oil cooler seals

[robbocop33]

Currently deep down into the bowels of hell on my 2006 cls320 diesel,i'm replacing the oil seals on the oil cooler right down the bottom of the V of the engine.
I am fitting the new improved purple viton seals,but as a backup could i put a 'very' thin smear of sealant in either of the two configurations shown here before i refit it?Thanks

[GreenV8S]

I can't see any harm from using a non-setting sealant such as Hylomar Blue.