If I remember correctly Campagnolo manual says there should be 8 - 12 mm gap between chain and RD roller when the chain is on the smallest cog and the small chainring. You can search Internet for Campy manuals - they explain things OK.
As for Squirt - I tried it once and then had to thoroughly clean the whole drivetrain. This wax based lube gave me a lot of dirt all over. These days I use only dry cleaning lubes, like T-9 spray, I like my drivetrain clean.