"I swear to avocado..."

An article about shopping at Target contained this phrase:

"I'm not a big shopper, but I swear to avocados that once I start roaming the aisles..."

I presume it originated as a polite way to avoid taking God's name in vain, but I've never encountered it before, either in conversation or six decades of reading.  I wonder if this phrase is a local colloquialism from some part of the country where I've never lived.