Problem is in doing something like that, and they find out, then there must be a good chance that they start asking what else have you been economical with the truth about? Even though there may be nothing, will they believe you?
I do one solo long haul back to Europe every year as I get much more annual leave than mrs Rush and always go Business: she ain't vastly happy about the cost, but she's OK with it. No point in hiding it, she can see when they pour me off the plane at Changi I wasn't up the back LOL!