You can't even change people's mind about motor oil. There's always some guy who asks, "Can I use xyzzy synthetic?" Then someone else shows him Mercury's oil FAQ that formerly said "No synthetics." So the first guy says, "Well xyzzy says it's OK for marine and Volvo uses synthetic in their GM based marine engines, so it must be OK."
At which point I usually think, "So why did you ask in the first place, *******?"
Best regards,
Frank C