I'm pretty sure it's Despite of all the string, and not "perspire", simply because it makes a lot more sense with the saying and the context (stringing someone along...with string; so even though he had a lot of string, he couldn't string this person along).
I'm pretty sure it's Despite of all the string, and not "perspire", simply because it makes a lot more sense with the saying and the context (stringing someone along...with string; so even though he had a lot of string, he couldn't string this person along).
Maybe.