[edr1924]

I think you can buy similar stuff pretty easy as car body sealant.
For example:
https://eshop.wuerth.de/Produktkategorie...%255B%255D

The link is just an example and should be no advertising.

Nevertheless in my opinion connectors should always be chosen to withstand the environmental conditions within the expected lifetime.
Such products may only be an workaround for plugs that are manufacturer given  

Best regards

Thank you for you insight Engolling, and you are absolutely right when you say that it's best to use the right connectors.  

But as I had this great stuff I use it when I can...

Regards,
Erik