I never got lectured in Indoc or by CPO not to use sick leave. I sicked out of two trips while on probation. Scared the hell out of me but I had no choice. Got the flu once and a wicked head cold the next time.
The second time, on the "backside" of the cold, I commuted down the night prior hoping I'd be better at show-time. When I went to bed the night prior I knew there was no way so I called scheds that night.
I asked them if they'd rather someone make the call early or try to see if they can tough it out. Her response was emphatic, "the earlier the better;" obviously it makes it easier for them to fill the line. Had to go see the CPO the next morning to get permission to non-rev back home. Me in the CPO office: "Sorry I'm not going to shake your hand, I'm sick." CPO: "Then what the hell are you doing at work?!?"
I never heard a thing about either sick-out except auto-generated emails detailing the need to call in well, and how you could WS/GS and pay back your sick bank if you flew on days of a rotation that were removed for the sick-out if you got healthy in time.
Oh, both times, I got sick because the Captain(s) on my previous rotation(s) flew sick, so it ain't just new FOs spreading the love.