Guddling is mentioned in the short story "The Mennans" by Robert Maclellan, in The New Penguin Book of Scottish Short Stories. IIRC, the line was:

"Tam whyles guddles oor troot, an he disnae aye gie 'em back."

I remember it vividly because I once read that story aloud for a gathering of friends. As part of my preparation, "guddles" was one of many words in that story that I had to look up.