KP-05 Mag leaking

[zapper]

Since May, I have put 1200 rounds thru it with no issues and 3-4 times per month.
Today, it blew 3 CO2 powerlets after tightened and pull trigger. I use a drop of silicone oil on each.
Called the dealer who advised that the O ring has dried out or valve needs
to be checked and that I should have always left a partial filled mag in between
sessions to keep O ring lubed.
I am pretty sure that I was not given that advice nor have I seen it on the very
few maintenance articles on the internet. Can anyone verify this and what can be done if I take it in? Still a newbie. Thanks!