Yikes.. you should definitely take the liquid post off and clean the poppets.
It might be fun to do it without releasing the pressure. I'm thinking old faithful geyser time, let us know how high it shoots beer.
I've had to do this multiple times when drinking something like a Pliny clone with tons of secondary leaf hops. Even the risk of infection on fermented out beer is relatively low. Just use good sanitation practices.
O rings for Posts, Dip Tubes and Cover. I prefer Silicon, little more expensive like $10 a pack vs $3 for Buna. Dip and Post are 100 in a pack, lids are 10 but you don't replace them as often.
9396K74 1 Pack Silicone O-ring, As568a Dash Number 109
9396K24 1 Pack Silicone O-ring, As568a Dash Number 111
9452K218 1 Pack Buna-n O-ring, As568a Dash Number 417
Order from HERE