hybrid expression?

[Allen D. Maberry]

Yesterday, on the evening edition of NPR's Marketplace, there was a story about the economic hardships faced by some California towns due to the huge deployment of US troops. At one point the reporter made the statement "They've got paychecks they're itchin' to burn." I've never heard this expression before and I first thought that it might be a blend of the cliches "itchin' to spend" and "burning a hole in one's pocket". Or alternatively, that in this case ("burn" might mean "spend") like the expression "blow one's paycheck on s.t." (although I've never heard "burn one's paycheck").  Has anyone else encountered this expression?

allen